Dr Liam Fox told BBC Scotland that the current technology required the retention of all four submarines.

The Royal Navy currently operates 58 nuclear-armed ballistic missiles and about 200 nuclear warheads on four Vanguard-class submarines at Faslane.

His comments follow speculation the fleet could be cut from four to three.

Britain operates a "Continuous At Sea Deterrent", which means a fully-armed submarine is on patrol in the Atlantic at all times.

However, the fleet is ageing and in 2005 the Labour government pledged to build four new submarines at a cost of £20bn.

Former Prime Minister Gordon Brown said in 2009 that he would be willing to cut the number of submarines from four to three in a bid to save money and contribute to global arms reduction.

In a speech last summer, Dr Fox said he would be prepared to follow suit, as long as the move did not compromise the UK's defences.

Rogue regimes

But speaking to a BBC Scotland documentary team, Dr Fox said: "At the moment the assessment is we need four.

"If you reduce the number you take an increased risk in your ability to deploy that deterrent at all times.

"So at the moment the technology says four. That's something that can always be kept under review."

Dr Fox said the coalition was committed to reducing the size of the UK's nuclear weapons stockpile, and the next generation of submarines would carry fewer warheads.

But he insisted that while other states were developing nuclear weapons, the UK needed to retain an independent deterrent.

He added: "We have rogue regimes like North Korea who are actually trying to develop nuclear weapons.

"We are seeing other countries potentially trying to develop nuclear weapons. And we cannot gamble with Britain's future security."

The coalition government has opted to delay work on the next generation of submarines until 2016.

Opponents of Trident believe the delay is an opportunity to get rid of Britain's entire nuclear deterrent.

The SNP's defence spokesman, Angus Robertson, said: "It's a weapon system which is unjustifiable.

"We can never use it. It's immoral, it's illegal, and frankly, we should be spending our money on more important things."

CND Scotland's Alan Mackinnon said the government's own security review found that the UK was far more at threat from terrorism, cyber attack or even natural disaster.

He added: "Nowhere down the line was there the threat of a nuclear attack from another country because that's just not on the horizon. It's just not going to happen."

"The two ships entered the Canal on Tuesday at around 5:45 am (0335 GMT), the official said. A normal journey through the stretch takes between 12 and 14 hours.

The patrol frigate Alvand and support ship Kharg were the first Iranian warships through Suez since the 1979 Islamic revolution, and are reportedly bound for Syria, a destination that necessarily involves passing Israel.

Egypt's official MENA news agency has reported that the request for the ships to transit the canal said they were not carrying weapons or nuclear and chemical materials.

The 1,500-tonne Alvand is normally armed with torpedoes and anti-ship missiles, while the larger 33,000-tonne Kharg has a crew of 250 and facilities for up to three helicopters, Iran's official Fars news agency has said.

Both ships were built in Britain during the 1970s for Iran, which ordered them before the Islamic revolution.

On Sunday, after a weekly meeting of his cabinet, Israeli Prime Minister Benjamin Netanyahu denounced the ships' arrival in the region as an Iranian power play.

"Today we are witnessing the instability of the region in which we live and in which Iran is trying to profit by extending its influence by dispatching two warships to cross the Suez Canal," he said.

"Israel views with gravity this Iranian initiative and other developments that reinforce what we have said in past years about the Israel's security needs," he added, according to a statement from his office.

Earlier this week, Israel Foreign Minister Avigdor Lieberman called the move a "provocation".

The animosity between Iran and Israel has grown under the presidency of Mahmoud Ahmadinejad.

The United States has expressed concerns about Beijing's military build up, with the Pentagon saying this month that China was developing "counter-space" weapons that could shoot down satellites or jam signals.

Beijing has become increasingly assertive in its ambitions on the high seas in recent years with plans to roll out its first aircraft carrier as the centerpiece in the emerging power's growing naval fleet.

The former Soviet aircraft carrier called the Varyag is currently being refurbished in the port city of Dalian in northeast China.

Speaking in Hong Kong on Monday Vice Admiral Scott Van Buskirk, commander of the US 7th fleet, said that the carrier "may come as early as this year," but did not elaborate or say whether it would be fully operational.

"It is our sincere hope that as China continues to develop a blue-water navy -- one which may soon include an aircraft carrier -- it will employ that navy in a way that is responsible and constructive," he added during a luncheon speech in Hong Kong.

Van Buskirk dismissed suggestions the US would cut its military presence in the region, saying there were an average of 70 US naval ships and aircraft operating in Asia daily, up from 50 to 60 a decade ago.

"Some worry that the US -- with our sluggish economy and continued military engagement in Afghanistan -- is weakening its position and its commitment to Asia," he said.

"I can tell you that our commitment to this region has never been stronger."

The naval commander also warned that the rash of sea piracy plaguing the coast of Africa was spreading eastward to southern India.

"Despite, or perhaps because of, the coordinated international efforts to fight piracy in the Gulf of Aden, we have seen the problem slowly creeping to the east into the Indian Ocean," Van Buskirk said.

"No one country can fight piracy alone," he added.

Last week, US Navy Admiral Robert Willard warned that Somali pirates were moving deeper into Asian waters amid international efforts to clamp down on the problem.

"The men and women of Boeing are honored to see this new capability directly benefit the nation’s brave servicemembers around the world," said Kory Mathews, vice president of F/A-18 and EA-18 Programs for Boeing. "The airborne electronic attack capability that the EA-18G brings to the fight is in high demand, so we are committed to continuing to deliver these aircraft to the Navy on budget and on schedule, just as we have with every F/A-18E/F."

The EA-18G is the only air combat platform that delivers full-spectrum airborne electronic attack (AEA) capability along with the targeting and self-defense capabilities derived from the Navy's frontline fighter, the F/A-18E/F Block II Super Hornet. A derivative of the two-seat F/A-18F Block II, the EA-18G's highly flexible design enables warfighters to operate either from the deck of an aircraft carrier or from land-based airfields. It is replacing the Navy's current AEA platform, the EA-6B Prowler, which has been in service since 1971. The EA-18G joined the Navy's aircraft fleet in 2008, when it was introduced to fleet training squadron VAQ-129.

Boeing, acting as the weapon system integrator and prime contractor, leads the EA-18G Growler industry team, which also includes Northrop Grumman, Raytheon and General Electric Aircraft Engines.

Chief of Navy Vice Admiral Russ Crane led the launch and said the event was enormously significant.

“These ships are officially known as Landing Helicopter Docks or LHDs and are the largest the Australian Navy has ever owned,” Vice Admiral Crane said.

LHD01's hull launch was held at the Navantia dockyards at Ferrol in northern Spain with the event having a distinctly Australian feel, as children of Australian diplomats in Spain joined the official delegation, waving Australian flags. A Canberra regional sparkling wine was broken over the Canberra Class ship’s hull. Vicki Coates, wife of the late Rear Admiral Nigel Coates, who commanded the previous HMAS Canberra, was the ‘launch lady’.

Vice Admiral Crane said that with a new generation in technology would come a new way of thinking in terms of how Navy would operate and crew this new capability.

“We are well progressed in our planning for the LHD arrival. I am confident we will have the people and the knowhow by the time the first LHD comes on line. Most importantly for now, this project is on time and on budget.”

Both ships will be based at Garden Island in Sydney. Crewed by all three services, the LHD will mark a significant strengthening of the ADF’s amphibious capability and tri-service culture.

First of class, HMAS Canberra (LHD01) will arrive in Victoria next year where it will be fitted out before being accepted into service in 2014 with sister ship HMAS Adelaide (LHD02) to follow the year after.

In a speech before the leaders U.S. Jewish organizations in Jerusalem, Lieberman said that the two Iranian warships would pass through the Suez Canal overnight and then head to Syria, a country with which Israel is formally at war.

Lieberman referred that the deployment of the warships was "a provocation that proves Iran's nerve and self-esteem is growing from day to day."

According to IsraelNationalNews.com, Iran announced it has planned that the warships would be deployed near Israel and dock at a Syrian port for one year.

Iranian news agencies in January announced the beginning of the country's year-long drills that would deploy warships from the Red Sea to the Mediterranean Sea via the Suez Canal.

The wind tunnel test validated the low-speed characteristics of a new wing, resulting in higher endurance and lower approach speeds. The new wing is also designed to increase aircraft dash speeds, decreasing the time to respond to potential threats.

“GA-ASI is committed to providing the Navy with swift delivery of a robust and versatile aircraft carrier-based UAS that meets or exceeds known requirements, provides measurable manpower savings, and assures best value,” said Frank W. Pace, president, Aircraft Systems Group, General Atomics Aeronautical Systems, Inc. “Reducing risk is a key component of this process, and our company has repeatedly designed and delivered low-cost, high-quality UAS, in part, because of our recurring commitment to invest in early development, as evidenced by this recent wind tunnel test.”

The 90-hour, eight-day test was conducted at the San Diego Air & Space Technology Center. The goal of the test, which was completed ahead of schedule, was to validate the low-speed characteristics of an updated wing in the approach, launch, and cruise configurations. The advanced design utilizes proprietary wing technology that enables high-speed flight, while also supporting excellent low-speed handling qualities desired for aircraft carrier landings.

The testing enabled GA-ASI to evaluate a specific set of configuration changes both quickly and economically. Wind tunnel testing also helps reduce program risk by providing empirical data to complement computational analyses. In addition, it provides the opportunity to correlate key performance data to analytical tools, such as computational fluid dynamics, and to validate various analytical methods.

Designed for fully autonomous launch and recovery from both USS Nimitz and USS Ford class carriers, Sea Avenger provides unmanned, autonomous, and long-endurance Intelligence, Surveillance, and Reconnaissance (ISR) capabilities responsive to the multi-mission requirements of carrier-based aircraft. The aircraft will provide for planning, control, tasking, collection, processing, analysis, and dissemination of actionable information in support of Navy missions.

An evolution of the combat-proven Predator UAS series with high-performance maritime payloads, Sea Avenger provides the highest operational value while being the only affordable system capable of meeting the Navy’s aggressive program schedule.

General Atomics Aeronautical Systems, Inc., an affiliate of General Atomics, delivers situational awareness by providing unmanned aircraft, radar, and electro-optic solutions for military and commercial applications worldwide. The company’s Aircraft Systems Group is a leading designer and manufacturer of proven, reliable unmanned aircraft systems, including Predator A, Predator B, Gray Eagle, and the new Predator C Avenger.

The structure is so big that it fills an entire hall at Govan and now extends beyond the doors onto the yard, providing a spectacular view from across the River Clyde.

Highlighting the skill and technology involved in British shipbuilding today, it took a team of 20 employees and remote controlled transporters just one hour to move 1,221 tonnes of steel over 100 metres across the shipyard. The hull section was then manoeuvred carefully into position to line up with the rest of the block.

Steven Carroll, Queen Elizabeth Class Project Director at BAE Systems’ Surface Ships division, said: “Seeing the mid section of the carrier come together brings into sharp focus the sheer scale and complexity of this engineering feat.

“With construction underway at six shipyards across the country, it is one of the biggest engineering projects in the UK today – second only to the London 2012 Olympics – and we’re all very proud to be a part of it.”

The two sections brought together today form the mid section of the hull up to the hangar deck and is referred to as Lower Block 03. Workers will now continue to outfit the block, which on completion will weigh over 9,300 tonnes and stand over 23 metres tall, 63 metres long and 40 metres wide. She is set to embark on the next stage of her journey to Rosyth in the latter part of this year, where HMS Queen Elizabeth will be assembled in the dry dock.

As a member of the Aircraft Carrier Alliance, BAE Systems is working in partnership with Babcock, Thales and the Ministry of Defence to deliver the nation’s flagships. This huge massive engineering project is rapidly gaining momentum and employs over 8,000 people across shipyards in Glasgow, Portsmouth, Appledore, Rosyth, Merseyside and Newcastle, with thousands more across the supply chain.

BAE Systems is also constructing the main stern section at its yard on the Clyde, which is the largest and most complex section of the carrier. At its Portsmouth facilities, work is well underway to construct the forward and lower stern sections of the hull, as well as the pole mast, whilst integration and testing of the ships’ complex mission system is underway at the Company’s Maritime Integration and Support Centre. Another team of BAE Systems engineers on the Isle of Wight is testing the advanced communication systems. The Company is set to begin work on the two island structures, which house the bridge and traffic control facilities, towards the end of the year.

Each 65,000 tonne carrier will provide the armed forces with a four acre military operating base which can be deployed worldwide. The vessels will be versatile enough to be used for operations ranging from supporting war efforts to providing humanitarian aid and disaster relief.

HMS Queen Elizabeth (R08) Specifications
Displacement	65,000 tonnes
Engines	4 x Rolls Royce Olympus TM3B gas turbines delivering 112,000 shp to two shafts
Length	284m
Max Beam	73m
Max Draught	11m
Complement	1500 (including air crew)
Aircraft	Total of 40 to include: Joint Combat Aircraft, Maritime Airborne Surveillance and Control (MASC) Aircraft and Merlin Helicopters.

To rapidly develop a new way to deliver information to the fleet, the Office of Naval Research (ONR) has created a unique acquisition approach that developers will outline at the Feb. 22-24 Institute of Electrical and Electronics Engineers (IEEE) conference in Miami.

The Command and Control Rapid Prototyping Continuum (C2RPC), a collaborative effort between ONR, the Program Executive Office Command, Control, Computers, Communications and Intelligence (PEO C4I) and Commander Pacific Fleet (COMPACFLT), will improve battle commanders' access to fleet readiness.

"This has been a change in how we do acquisition, in that we've been doing it in an accelerated timeline," said Gary Toth, ONR C2 program manager. "It's been a true partnership between science and technology (S&T) and the operational user."

The effort is also the model for rapid acquisition at PEO C4I and is changing how that command does business too, he said.

Toth will deliver the keynote address on the first day of the IEEE conference on Cognitive Methods in Situational Awareness and Decision support.

C2RPC is a software application hosted on web servers at the Space and Naval Warfare Systems Command (SPAWAR) Systems Center Pacific in San Diego. The application runs from standard web browsers at COMPACFLT in parallel with operational, live data.

The next-generation C2 technology goes beyond tracks on a map. It provides continuous rapid delivery of warfighter capability, through direct fleet involvement, to support time sensitive decision making.

With C2RPC, crucial information about fleet readiness, gathered from multiple sources, will be available in one place at the same time. For example, logistics or ammunition load out will be accessible by operators on one computer.

Another advantage of the command and control system is the ability to geo-locate all of the resources under the command of warfighters--from allocation, to position, to available capabilities--to meet a host of mission scenarios from humanitarian relief to major theater conflict.

ONR support has been crucial to this effort, bringing the vision of what is possible in the future, said Capt. Bruce Stewart, director of operations, Pacific Fleet.

"You can make informed, aligned, decisions through the chain of command because everyone will be looking at the same information," Stewart said. "It's a great system, a great model, for how to develop systems with close collaboration of the fleet."

Not only has C2RPC been released to Pacific Fleet for operational evaluation and day-to-day use, the tool is being used to provide daily briefs to Navy leadership and Adm. Patrick Walsh, commander Pacific Fleet, said Gary Shaffer, deputy technical director, chief engineer for emerging technologies (PMW-150), PEO C4I.

Sailors are becoming more accustomed to the technology that provides them with a global picture of fleet resources, Shaffer said. "We are in discussions with the 5th, 6th, 7th and 10th fleets," he said. "They all want C2RPC."

ONR and PEO C4I are also preparing to deliver for operational evaluation a capability called MAGIC MIRROR, which provides a 24-7 command and control capability to monitor and assess the Intelligence Architecture. "We will make the first delivery to PACFLT in mid-February for operational evaluation," Shaffer said.

Sailors will get to work with MAGIC MIRROR during the annual weeklong Terminal Fury exercise. The training tests Pacific Command's ability to respond to the broad challenges it faces in the region.

Historically, carrier aircraft have been highly specialized and designed specifically for the role. In the majority of cases, there is little or no commonality between the aircraft operated by a nation’s air force, and the different aircraft performing the same role in the Navy. Design decisions taken in order to optimise an aircraft for carrier operations can lead to trade-offs elsewhere – such as additional weight and low-speed handling characteristics that compromise performance in other areas of the envelope.

A classic example today is the F-18 in all its versions, heavy, slow and not capable of facing the most advanced threats emerging around the world.

For a number of years, Eurofighter GmbH and its industrial partners have been studying the feasibility of adapting Eurofighter Typhoon for the naval role. These studies have included the assessment of required design changes, piloted simulations to refine the aircraft’s handling qualities and discussions with key suppliers. The studies indicate that these changes are feasible, and would lead to the development of a world-beating, carrier-based fighter aircraft.

READY FOR LAUNCH
Modern carrier aircraft typically take off with the use of a catapult that attaches to the nose gear. These catapults are expensive to procure, maintain and operate. Catapult launch also leads to a heavier aircraft as a result of the additional weight on the aircraft’s structure.

Typhoon is well known for its exceptional thrust-to-weight ratio which has been regularly demonstrated at air shows and in customer flight trials. It also allows the aircraft to take off from a carrier using a “ski-jump”. Detailed simulations have shown that the aircraft will be able to take off in this way with a full weapon and fuel load – providing a nation with a truly potent naval aviation capability.

LANDINGS
Clearly one of the major challenges for any carrier-based aircraft is the arrested landing. Carrier aircraft fly a steep approach path and are brought to a halt rapidly by the arrestor gear. This leads to much higher loads being generated than would be the case for a land-based aircraft. Navalized Typhoon tackles this problem in two ways.

• The introduction of a thrust-vectored variant of the Eurojet EJ200 engine would allow for a reduction in the aircraft’s approach speed and the resulting landing loads. Thrust vectoring (Engines with TVN are already tested on bench) could be fully integrated into the Typhoon’s advanced Flight Control System (FCS), allowing the pilot to focus on flying the approach path while the FCS manages the engine nozzle position.
• The basic design of Typhoon also works in its favour during an arrested landing. The aircraft’s structure is exceptionally strong, having been designed from the outset for the high dynamic loads associated with extreme air combat maneuvering. This helps to minimize the structural changes required to enable carrier operations – usually seen as the biggest obstacle to developing a carrier-based variant of the aircraft.

SIMILARITIES
In any discussion of a navalized Typhoon, the differences from the land-based aircraft are the natural focus. However, one should also focus on the similarities. A key design driver for a navalized Typhoon has been to maximize commonality between the two variants. Design changes are minimized, allowing for many spare parts and test equipment to be shared across a customer’s air force and navy fleets. The sensors, systems and weapons available to both variants will be common, allowing for a reduction in the aircrew training requirements. And in addition, the two variants will benefit from a common upgrade path – new capabilities will be available to both the air force and navy in similar timescales.

The introduction of Thrust Vectoring potentially provides an additional boost to Typhoon’s capability. The ability to change the angle of the engines’ thrust will allow for a further enhancement in Typhoon’s already outstanding maneuverability, supercruise performances, fuel consumption and the handling of asymmetric weapon configuration.

When this is added to capabilities such as the Helmet Mounted Symbology System (HMSS), AESA radar and advanced air-to-air and air-to-surface missiles, the result is a truly world-beating multi-role aircraft. One that could also operate from an aircraft carrier.

NO COMPROMISE
Eurofighter has already discussed a navalised Typhoon with a number of potential customers and is keen to pursue this exciting new phase in Typhoon’s development. Naval aviation will undoubtedly continue to provide nations with a flexible option for projecting power over the coming years.

In an increasingly affordability-conscious world, commonality between a nation’s air force and naval aviation fleets will be of increasing importance. A navalised Typhoon can deliver this commonality, without compromising on capability.