US election 2024: Why the world is watching so closely

Only two states have chosen which Republican they want to take on Democratic President Joe Biden but it's almost certain to be Donald Trump. It's an election campaign being watched not just in the US but around the world.

After recently spending a few weeks in Europe, the subject of America's presidential election was a constant topic of intense curiosity and concern among the people I spoke to. And no wonder.

The US is currently involved in two hot wars, Ukraine and Gaza. Meanwhile, US-China relations have deteriorated and tensions in the Asia Pacific region have risen.

Closer to home, Central American nations are under the spotlight as a growing number of migrants are trying to get to the US through a border which seems more porous by the day. And this week there were US-led air strikes against Houthi rebels in Yemen.

There is almost no area of the world where American leadership doesn't matter.

The prospect of Republican Donald Trump returning to office, with his America First foreign policy agenda, adds more uncertainty to an already tumultuous picture.

Some countries look forward to his return. But many of America's allies are more fearful about the possible comeback of an unorthodox president they found hard to deal with the first time around.

Democratic Senator Chris Coons, who sits on the Foreign Relations Committee and is also co-chair of President Biden's re-election campaign, told me that in every meeting he's had with foreign leaders or foreign secretaries, at some point they raise the question of whether American voters could really turn once more to President Donald Trump.

So, while this may be a US election, other countries are deeply invested in the result.

In no capital in the world are they watching this campaign as closely as they are in Kyiv. The fate of the war arguably depends on the outcome.

"If the policy of the next president - whoever he is - will be different toward Ukraine, colder or more inward-oriented… then I think these signals will greatly affect the course of the war," President Volodymr Zelensky said recently.

He didn't name names but Mr Trump has said he would end the war "in 24 hours" of being elected, although he hasn't explained how. The Ukrainians are concerned he would push for negotiations that wouldn't favour their cause.

That would go down well in Russia, where the media has been particularly supportive of Trump, and some have criticised efforts to remove him from the ballot in 16 US states.

The Kremlin-controlled channel NTV was scathing. "This is real meddling in the election and the undermining of democracy by Americans themselves. No Russians or Chinese would even dream of this," NTV correspondent Anton Ponomaryov told viewers, with no hint of irony.

The implications of a shift in US policy would be felt beyond Ukraine's border and would particularly worry those European states that neighbour Russia.

Further afield, other American allies may decide the US is not a reliable security partner. One US senator raised the prospect of Japan developing its own nuclear arsenal if America stops helping Ukraine. Tokyo, he told me, could decide the American nuclear security umbrella simply has too many holes in it.

There's also the prospect that a re-elected President Trump would act on his desire to pull America out of Nato, effectively crippling the military alliance. Two people with ties to the Trump campaign have told me he does plan to do just that.

Europeans, says Senator Coons, are right to be anxious.

"The US and its European allies have a significant common challenge. Together we have to show the world that Putin can't outlast us and that [Chinese] President Xi's vision of authoritarianism is not the best for the world."

The other hot war, the conflict in the Middle East, has clearly shaken up US politics in different ways - younger Americans and Arab Americans so oppose the White House's support for Israel that Joe Biden could even lose a state because of it in the election.

But the reaction of Israelis to US politics is perhaps even more surprising. Israelis used to favour Trump over Biden by large numbers, but a December 2023 poll by the Midgam group showed a dramatic shift in support towards President Biden.

A survey of Israeli media shows the paradox isn't lost on Israelis that their newfound love of Joe Biden may hurt his chances of being re-elected. The business daily Calcalist carried the headline "Biden's support for Israel strengthens Trump ahead of the elections."

Other Middle Eastern countries may welcome a change in Washington, however.

During the 2020 campaign, for example, Joe Biden called Saudi Arabia a pariah state. Then months into his presidency a disastrous US pull-out from Afghanistan has the Taliban firmly in control.

"I do think our Middle Eastern partners would universally prefer a Republican president to Biden," says Matthew Kroenig, a former US defence department official who now works at the Atlantic Council think tank.

For some heads of state in the Middle East, a transition away from Joe Biden may mean less interference and criticism from Washington.

A Republican president, says Kroenig, may be less likely to critique Israel about the way it has handled the war in Gaza or to lecture Saudi Arabia about its human rights record.

Independent Senator Angus King has just returned from a cross-party Senate delegation to the region. He told me the political paralysis in the US is also being noted abroad.

"Hamas and Putin have similar strategies now - wait for the West to lose its will and wait for America to be eaten by its own divisive politics."

From Beijing to Buenos Aires, people follow the fortunes of the US election candidates and tune in for the results. It has a global audience like no other election. Because America still matters like no other country.

But this, my sixth presidential election, seems to have an international focus that is more intense than ever.

Partly because the US is so involved in so many areas of the world but also because of what happened after the last one. The events of January 6th 2021 revealed the precariousness of America's democracy.

Now the world wants to know how well the country will fare in its next big democratic test.

As well as the host of crises that America already is confronting, the next president will also have to deal with the unexpected.

2023 was the hottest year on record. 2022 brought war in Europe. 2020 brought a global pandemic no one saw coming.

The US can't tackle any of those things without strong global alliances - which is why the world's reaction to this election doesn't just matter to the rest of the world.

It matters to America too.

Additional reporting by BBC Monitoring which tracks, translates and analyses media around the world for BBC News, governments, NGOs and other international organisations