NATO: US military presence in Europe

A U.S. carrier strike group — a large fleet of warships — is a powerful symbol of American military power and a signal of its readiness to defend allies and deter enemies.

The presence of such a force in the North Sea in recent weeks is intended to reassure European allies, despite the political uncertainties at home.

American military power has helped protect Europe for the last 75 years – but the US presidential election raises the question: for how much longer?

Military commanders do their best to avoid politics.

But for a group of journalists invited aboard the USS Harry S. Truman, the US presidential race was high on the agenda. The question was: Will America continue to support Europe?

Rear Admiral Sean Bailey said: “What I can tell you is that we are firmly committed to our alliance and to NATO.”

But he is not the one who will decide US foreign policy, and his answer is unlikely to dispel doubts.

German Defense Minister Boris Pistorius knows that change is coming.

Asked about the likely impact of the U.S. election on Europe last week, he said it was a question of whether America would do “a lot less or a little less.”

He didn't name any names, but Donald Trump is likely to do far less.

The USS Harry S. Truman proudly bears the name of the president who helped found NATO 75 years ago.

But a second Trump term in office could once again shake the foundations of the alliance.

The Truman Doctrine of providing military, economic and political support to threatened democratic nations is very different from Trump's “America First” policy.

He recently said Russia can “do whatever they want” with allies that don’t spend enough on defense.

Any US withdrawal from Europe would leave a huge gap.

The USS Harry S. Truman is a testament to what America has to offer in size and numbers – with 5,000 crew members and more than 60 aircraft.

The Royal Navy carrier HMS Prince of Wales sailing nearby was a reminder of Europe's more modest defenses.

The British aircraft carrier sailed with an air wing of a few helicopters and eight F-35 jets – a weak reflection of US military clout.

In total, more than 100,000 US military personnel are stationed in Europe.

The last time he was president, Trump threatened to withdraw some of these forces. If elected, he could do the same thing again.

Many Republicans believe Europe should look after itself. That's certainly the view of Elbridge Colby, a senior Pentagon official in the last Trump administration.

He says the US should “hold back” its forces from Europe to focus on the threat from China.

The election will also impact US military aid to Ukraine – America is by far the largest military supporter.

But a senior NATO official, who did not want to be named, recently told the BBC: “Regardless of who wins, the share of the American contribution to Ukraine, relatively speaking, is likely to decline.”

Europe cannot expect the US to continue making an “outsized” contribution, he said.

The reality is that America's military focus has already shifted eastward to the Indo-Pacific region and the rise of China.

The Pentagon identifies China as its biggest security challenge. China now has a larger navy than the USA. A fleet the size of the entire Royal Navy is built every two years.

The sailors and pilots aboard the aircraft carrier realize that there is also a pivot point to the east.

Cdr Bernie Lutz has spent much of his naval career flying F-18s from a U.S. aircraft carrier in the Pacific and the Middle East.

He realizes why they are now sailing in European waters. “There’s a lot going on,” he says.

But he adds: “I think the Pacific theater is the bigger, overarching long-term goal.”

Like the rest of the aircraft carrier's 5,000-strong crew, it has not yet been told where they will sail next – but it has been widely reported that the USS Harry S. Truman will soon be on its way to the Middle East.

This region will also remain a challenge for the next president.

Captain Dave Snowden says he's happy to carry the banner of de-escalation or deterrence, or even sail into danger – wherever the bearer is sent.

However, the lack of a serious foreign policy debate in the election reflects a reluctance to directly engage in further wars.

America will continue to be the world's preeminent military power.

The question is how the next president will use it.