As Americans go to the polls Tuesday, the world is closely watching to see whether Vice President Kamala Harris or former President Donald Trump emerge victorious.  

The next US president will not only command the most capable military in the world, he or she will also have the ability to help shape – or reshape – the country’s foreign policy. And while US elections are seldom decided on global issues, escalating conflicts around the world are certainly expected to influence the decision of some American voters.  

The election comes as the US is facing a plethora of international challenges – from war in Ukraine to escalating violence in the Middle East to an increasingly assertive China – amid arguably diminished global influence.  

That waning power was evident at this year’s UN General Assembly in New York in late September. Addressing the annual gathering of world leaders, President Joe Biden called for an end to the violence in Lebanon, urged Israel to do more to protect civilians in Gaza and demanded Russia end its war of aggression against Ukraine. Those demands all fell on deaf ears. 

For Brett Bruen, a former White House official in the Obama administration from 2013-2015, it was the latest sign that the world has “fully entered a post-American era.”  Such a post-American world, as Bruen described it, doesn’t mean the US is absent from the world stage, but rather that Washington’s global influence and impact is “substantially reduced.”   

“The world Biden will hand off, either to Vice President Kamala Harris or former President Donald Trump, is even worse in a lot of ways than the one he inherited,” he said on the sidelines of the General Assembly. 

Bruen, who served as former President Barack Obama’s director of global engagement, referred to the burgeoning conflicts in the Middle East, the war in Ukraine, and growing tensions between the US and China over Taiwan as the biggest international challenges facing a new administration.  

America’s gradual withdrawal from the world stage has left a power vacuum, and whether any other nation can fill it remains to be seen. Nations like China, Russia and India are vying to expand their spheres of influence as the US looks inward – what Bruen calls a “competition between mediocre powers.”  

With the US presidential election days away, the question is whether either Harris or Trump is capable of – or has the political will – reasserting US leadership on the world stage.  

Former President Trump’s isolationist ‘America First’ philosophy has particularly undermined US leadership abroad. He has threatened to stop protecting NATO allies if countries don’t contribute more to their national defence and questioned the transatlantic alliance’s support for Ukraine against Russia. At the same time, he’s called for across-the-board tariffs, including against European allies like Germany.  

“Without trying to sound alarmist, I do think that a Trump presidency would be irrevocably damaging for the US and the West,” said Bruen.  

Harris on the other hand is expected to build on what Biden had promised but couldn’t deliver. She wants to strengthen America’s traditional alliances and increase Washington’s influence in regions that have often been an afterthought, such as the Pacific Rim or Africa.  

That’s a tall order, particularly for a candidate like Harris who lacks much foreign policy experience. Biden had promised to repair relations with America’s traditional allies. And while he certainly made progress, his embrace of economically protectionist measures and his hesitancy around more forcefully arming Ukraine has led to criticism abroad.  

Harris – should she win the election – may lean on America’s European allies to push her foreign policy agenda, said Bruen. He believes Harris needs the support of countries like the United Kingdom, Germany and France to make her mark on the world stage. But that may be easier said that done, given domestic political pressures in each of those countries.  

“It’s not clear Emmanuel Macron, Olaf Scholz or even Keir Starmer – really any of them – have the capability to do so right now, based on their weakened domestic standing,” he said of the French, German and British leaders.  

Despite Europe’s own challenges, relying on traditional partners could help Harris overcome her lack of experience and increase her chances of effectively executing her foreign policy goals.  But for Europe – long reliant on US security guarantees – the bigger question is whether either candidate actually has the ability or the desire to reverse course on America’s slow retreat from the world.