As debate over the rightful ownership of the Falkland Islands bursts back into life, Dr Gareth Evans compares the British and Argentine naval forces of 1982 with those of today, to find out just how much has changed since the first confrontation.

Argentine destroyer ARA Almirante Brown.

On the morning of the 2 April 1982, the task of defending Port Stanley against a 600-strong Argentine invasion force fell to a British contingent of just 80 servicemen - 68 Royal Marines and 12 sailors from the ice patrol ship HMS Endurance - along with a handful of local reservists.

"A recent report from Strategic Defence Intelligence predicted that Argentina's defence budget will see a compound annual growth rate (CAGR) of 15.87% over the period from 2011 to 2015."

By a quirk of fate, that represented almost twice the usual number of personnel routinely stationed on the Falkland Islands at the time, as the attack had come during a changeover.

Thirty years on, and today's military presence is rather more substantial. Three Royal Navy vessels, a patrol ship, an auxiliary support ship and either a frigate or a state-of-the-art destroyer - such as the Type 45 anti-aircraft destroyer, HMS Dauntless, recently sent to the South Atlantic - guard the sea lanes, bolstered by the rumoured presence of a conventionally armed, nuclear-powered submarine.

The islands are also now home to a garrison of 1,200, with aerial defences provided by a series of strategically placed Rapier missile batteries and four Typhoon fighters, with logistics support from a Hercules C130 transporter and a VC10 tanker.

While the islands themselves are clearly better defended, during the intervening decades there have been changes elsewhere too.

From the British perspective, the Falklands conflict was predominately a naval campaign, involving a task force which ultimately amounted to 127 ships, consisting of 43 Royal Navy vessels, 22 from the Royal Fleet Auxiliary and 62 merchant ships.

While Argentina's Navy played a very small part in the fighting by comparison - and almost none at all after the subsequently much-debated sinking of the ARA General Belgrano - examining the current maritime power of the two combatants offers some interesting insights into how military spending has shifted over recent years.

Defence spending since the Falklands War

British defence spending

According to the latest SIPRI Military Expenditure Database, during the era which included the Falklands conflict, Britain's military budget represented around four percent of GDP - something which the conflict itself helped to increase.

Defence reviews are not a new phenomenon, and the UK's spending had been the subject of major cuts during the late 1970s, which, ironically, would have meant that a number of the vessels involved in the war would not have been in service if Argentina's military junta had delayed the decision to invade by a few months.

The conflict in the South Atlantic made it clear that the Royal Navy needed to maintain its expeditionary capabilities as well as fulfil its Cold War role. The impending cuts were abandoned as a result, and the experience undoubtedly helped mitigate further threats to the naval budget throughout the rest of that period.

Today, cuts are once again on the agenda, with defence spending now accounting for 2.7% of GDP and, in the wake of the Strategic Defence and Security Review, they are to face a five percent reduction - £1.72bn in real terms - by 2013/14. Nonetheless, Britain's military budget still ranks fourth in the world.

Argentina's defence spending

Argentina, by contrast, languishes down in 49th place - but that sort of rather simple comparison does not begin to tell the real story. While here the SIPRI figures also show the proportion of GDP spent on defence has fallen slightly - from 1.4% then to one percent today - that masks the increase in actual cash terms driven by the growth in the country's economy.

As the 1980s drew to a close, Argentine military expenditure, expressed in US Dollars at constant 2009 prices and exchange rates, was $2.7bn. On the same basis, in 2010, it reached $3.3bn - and it seems set to grow further.

A recent report from Strategic Defence Intelligence predicted that Argentina's defence budget will see a compound annual growth rate (CAGR) of 15.87% over the period from 2011 to 2015, reaching a final total of $5.5bn. In respect of the Argentine Naval allocation, the authors forecast it will increase from the average of 25.3% of the country's total defence budget between 2006 and 2010, to 25.5% over the years to 2015.

An artist's impression of the HMS Queen Elizabeth and HMS Prince of Wales at sea.

British and Argentine naval fleets

Britain's naval fleet

Put bluntly, having the fourth largest military spending does not automatically equate to having the fourth largest military, and nowhere is that better reflected than in the British naval fleet.

"Should a similar need arise today, the upsurge of 'flags of convenience' might see HM Government looking to charter foreign ships."

At the end of the 1980s, the Royal Navy had two aircraft carriers, seven amphibious ships, 13 destroyers and 35 frigates.

Today, the like-for-like comparison sees Britain carrierless - and left reliant on helicopter carriers for some years to come - with just 18 active major surface combatants, comprising of five destroyers and 13 frigates.

In addition, there are two landing platform docks and a total of 11 nuclear powered submarines, of which four are ballistic missile submarines and the remaining seven are conventionally-armed, fleet submarines. A further seven vessels are currently being constructed - the two Queen Elizabeth-Class aircraft carriers, the last of the Type 45 destroyers and four Astute-Class submarines.

Apart from the loss of fixed-wing carrier capability, arguably the biggest potential change in British maritime muscle post-Falklands, however, lies in the drastic reduction of merchant vessels sailing under the British flag. In 1982, requisitioned ships accounted for nearly half of the task force. Should a similar need arise today, the upsurge of 'flags of convenience' might see HM Government looking to charter foreign ships.

Argentina's naval fleet

"Today's Argentine Navy boast two amphibious vessels (one command ship, one cargo ship), four destroyers, nine corvettes and three submarines, but like the UK, no carrier."

Argentine's core fleet at the start of the Falklands conflict was comprised of six destroyers (two of them Type 42s), three corvettes, one cruiser, one ex-Royal Navy Colossus-Class carrier (the former HMS Venerable) and two submarines (one a modern Type 209, the other a WWII vintage Guppy-type).

Despite playing a comparatively minor role in the conflict, Argentinean maritime losses amounted to one cruiser, one submarine, four cargo vessels, two patrol vessels and a spy trawler, and the experience clearly shaped naval thinking in the aftermath of defeat. The main fleet was transformed, with modern Meko 360 and 140 type vessels replacing the antiquated Fletcher and Gearing Class destroyers, and two Thyssen TR-1700 Class vessels being acquired in the place of the single Guppy submarine.

Today's Argentine Navy boast two amphibious vessels (one command ship, one cargo ship), four destroyers, nine corvettes and three submarines, but like the UK, no carrier. The Falklands-era ARA Veinticinco de Mayo was decommissioned in 2000.

Perhaps the most curious fact to emerge from the comparison is that, despite the war comprehensively demonstrating the value of close air support - and the awful vulnerability of its absence - both nations have to a large degree turned their backs on naval air-power, at least for the moment.

Just how long the current situation is allowed to persist, where each navy's pilots have to depend on their respective allies' carriers for deck space, remains to be seen.

Type 21 frigate HMS Antelope returns to San Carlos Water on 23 May 1982. She was fatally damaged and sank the next day.