On NATO’s border with Russia, soldiers with the UK’s Yorkshire Regiment recently joined Estonians in a celebration of the 100th anniversary of the Royal Navy’s critical intervention in the country’s battle for independence against the Bolsheviks.

Schoolchildren clambered over a huge Challenger 2 battle tank, an AS-90 artillery gun and an armoured personnel carrier.

To all appearances, it was a stirring reminder of Britain’s commitment to European defence, Brexit or no Brexit.

But the battalion, based in Estonia as a critical part of NATO’s response to Russia’s invasion of Crimea in 2014, is the polished surface of a hollow shell.

Our military has been badly damaged by austerity and political choices that have consistently favoured symbol over substance in a struggle to remain a global power.

Syria bombings: US, UK and French military air strikes wreckage Show all 13 1 /13 Syria bombings: US, UK and French military air strikes wreckage Syria bombings: US, UK and French military air strikes wreckage The wreckage of the Scientific Studies and Research Centre in the Barzeh district, north of Damascus, which was targeted by the US, UK and France air strikes. AFP/Getty Syria bombings: US, UK and French military air strikes wreckage A Syrian soldier films the damage of the Syrian Scientific Research Center surrounded by papers and rubble. AP Syria bombings: US, UK and French military air strikes wreckage Firefighrers extinguish smoke that rises from the damage. The Pentagon says none of the missiles filed by the U.S. and its allies was deflected by Syrian air defenses, rebutting claims by the Russian and Syrian governments. AP Syria bombings: US, UK and French military air strikes wreckage The wreckage of part of the Scientific Studies and Research Centre compound . AFP/Getty Syria bombings: US, UK and French military air strikes wreckage Part of a building collapsing, surrounded by the wreckage. AFP/Getty Syria bombings: US, UK and French military air strikes wreckage Further damaged to the Scientific Studies and Research Centre compound. AFP/Getty Syria bombings: US, UK and French military air strikes wreckage Lt. Gen. Kenneth McKenzie, the director of the Joint Staff at the Pentagon, also says there also is no indication that Russian air defense systems were employed early Saturday in Syria. AP Syria bombings: US, UK and French military air strikes wreckage A Syrian soldier sprays water on the wreckage. AFP/Getty Syria bombings: US, UK and French military air strikes wreckage Syrian state news agency SANA reported several missiles hit a research centre in Barzeh, north of Damascus, "destroying a building that included scientific labs and a training centre". AFP/Getty Syria bombings: US, UK and French military air strikes wreckage A Syrian soldier films the damage. AP Syria bombings: US, UK and French military air strikes wreckage Damage to the Scientific Research Center building that was hit by the strikes. EPA Syria bombings: US, UK and French military air strikes wreckage The Scientific Studies and Research Centre was one of the targeted buildings by the US, UK and France. AFP/Getty Syria bombings: US, UK and French military air strikes wreckage Further damage to the centre. EPA

For a military that once spanned the globe, this squad of some 1,000 troops and assorted armour represents the largest British battle group deployed anywhere in the world.

Budget cuts have led to sharp reductions in troops, equipment and investment, and analysts warn that Britain is no longer capable of defending its homeland by itself.

Britain remains a nuclear power and a member of the UN Security Council.

It is one of the few countries able to fight on land, sea and air, and its intelligence capability is world class. In a post-Brexit world, should that come about, Britain’s role as a military power will be vital to its self-image, its geopolitical clout and its relationship with the United States.

But the budget cutbacks have contributed to growing doubts in Washington about whether Britain remains capable of fighting a war alongside the US military.

The British House of Commons Library assessed that in real terms, between 2010 and 2015, Britain’s defence budget fell by £8 billion, a cut of 18 percent compared with the 2009-10 budget. The budget has stabilised since then, but has not grown significantly.

Experts say that France is gradually supplanting Britain as the leading European military ally of the United States, further weakening the “special relationship” between Britain and America — a deep concern at a time when both Brexit and the isolationism of President Donald Trump are weighing on British security officials.

“Over the last 10 years, there is a steady decline of Britain as the partner of first choice for the US military,” said former US assistant secretary of defence for international security affairs, Derek Chollet.

“Libya in 2011 was really the last gasp of Britain as a leading military power. Brexit is just a continuation and acceleration of the extended existential crisis.”

Britain has fought alongside US troops in Iraq and Afghanistan, and joined the fight against the Islamic State.

But “the forever wars” have badly sapped British equipment and morale, and have deeply damaged faith in the judgment of the United States.

The public’s appetite for military adventures is waning, while Jeremy Corbyn has spent decades opposing nuclear weapons and NATO itself.

Perhaps most telling of our lower military status, the United States’ last three formal defence reviews have been predicated on the assumption that Britain will never again fight a war without America.

“That’s a big concession to make,” especially in the time of Mr Trump, said Kori Schake, a former Pentagon official who is now deputy director of the International Institute for Strategic Studies in London.

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Upon triggering Brexit, she added, “Britain made a big bet on the US relationship, so that explains a lot of the jangled nerves now.”

Oddly, the problems with the British military echo the debate over Brexit.

“What does Britain actually want to be in the world?” Ms Schake said. “They don’t know the answer.”

For Julian Lindley-French, a defence analyst and senior fellow at the Institute of Statecraft in London, austerity-shrunken Britain is “retreating behind a nuclear shield, no longer with the popular will or the capacity to defend the Continent”.

Britain, he added, “wants the symbols of power — the nuclear deterrent and the ensign on the aircraft carrier.”

In an interview, defence minister Gavin Williamson spoke proudly of securing another £1 billion over the next two years for a military budget that would total £38.4 billion in fiscal 2020.

That represents 2.1 percent of gross domestic product, just over NATO’s guideline of two percent, although since 2015 it includes spending for military pensions and intelligence.

Britain cannot have “the scale or the mass” of the United States, he said.

“But we are the only other country in NATO that can lead the way the US can lead, the only country in Europe that has the full range of capabilities.”

Britain is making difficult spending choices, Mr Williamson said, about “how we use our technology and new ideas to improve the lethality we have on the battlefield” in the face of new threats.

As for NATO, he said, “I struggle to think of a request from NATO that Britain hasn’t met”.

Another billion helps, but in June, the House of Commons Defence Committee called for an extra £20 billion in military spending, up to three percent of GDP, a recommendation unlikely to be met.

It is not just the level of spending, however, that is hurting the British military. More important is how the money is being spent.

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The expenditures focus on two projects: replacing four ageing nuclear missile submarines and building two world-class aircraft carriers, with all the ships, planes and submarines required to protect them and the F-35B fighter jets to put on them.

The nuclear program alone is costing £5 billion a year, about 14 percent of the annual defence budget, with total costs for the new subs estimated at £31-41 billion.

Once you throw in the cost of attack submarines to protect the nuclear subs, total spending on the nuclear enterprise rises to around £70 billion over the next decade, said Malcolm Chalmers, deputy director general of RUSI, a military research centre.

That comes to nearly 18 percent at today’s budget and GDP levels.

The combined impact of austerity-era cutbacks and spending choices has hit the army the hardest of all the services.

Now smaller than at any time since Waterloo, it has failed to meet even modest recruitment goals, in part because of an embarrassing effort at outsourcing.

It is still several thousands short of its goal of 82,000 “fully trained regular army soldiers”, despite downgrading what it means to be “fully trained”, as well as falling short of its goal of 30,000 in the army reserve.

In other areas of modern warfare, however, Britain’s capacities are more highly regarded, especially in cyber-defence and cyber-offence, intelligence and space.

Tom Tugendhat, a lieutenant colonel in the army reserves who served in Iraq and Afghanistan and is now chairman of Parliament’s Foreign Affairs Committee, said: “The fundamental problem in defence is always personnel. Our army and navy are too small, and our reserves are not even vaguely close to being fully manned”, partly because of the new carriers and nuclear submarines.

But the big-ticket items are a measure of British resolve, he said. “The UK will be the only European country with two aircraft carriers, the ability to deploy force and the willingness to do it,” he added.

Island Britain “has always used a heavy navy to project a light army”, while European forces usually have the reverse.

NATO may complain about Britain’s not providing territorial forces to deter Russia, “but it’s Germany that should be providing them”, he said.

In Tallinn, the Estonian capital, the defence minister, Juri Luik, praised the British presence as a symbol of solidarity.

Estonian troops fought in a British brigade in Afghanistan, he said, “so it’s a close relationship”.

Whatever the military’s current shortcomings, Mr Luik said, “the British have a real military culture. They understand a battle is a battle. And they can take casualties.”