Rest of world watches US turmoil with growing alarm

The images of a bloodied Trump being rushed from the stage captured global attention, and for many painted a picture of an America increasingly at odds with itself—a country that has a strong economy but a dysfunctional and dangerously divided political landscape.

In foreign capitals around the globe, the attempted killing of Trump and Biden’s repeated gaffes have changed the political and diplomatic calculus, sending many governments scrambling to prepare for a second Trump presidency as the most likely scenario, due to growing voter concerns about Biden’s mental fitness and a likely groundswell of sympathy for Trump following the failed attempt.

One British newspaper columnist said Trump was now “unstoppable." A report Monday by South Korean brokerage Eugene Investment & Securities was titled “Trump’s Rise and Biden’s Fall," and featured side-by-side photos of a bloodied Trump pumping his fist on Saturday and Biden’s stumble at a U.S. Air Force Academy event last year.

The assassination attempt, alongside the debate about President Biden’s age, has also given new life to Russia’s favorite foreign-policy narrative: America’s supposed precipitous decline.

Top Russian officials on Sunday talked about the “suicidal supposed condition" of American democracy, predicting that the country was on the brink of a civil war. The Kremlin blamed the Biden administration for creating an atmosphere that provoked the attack.

“Russia has a proven track record of pouring gasoline on U.S. problems," said Alexander Gabuev, the director of the Carnegie Russia Eurasia Center. “For the Kremlin…the shooting and the debate around Biden’s age just reinforces their belief that America, as powerful as it is, is actually on its deathbed," he said.

Some commentators close to the government in China also piled on, given the longtime belief in Beijing that America is in a period of decline as the world’s singular power. “It’s garbage time for American-style democracy," Han Peng, a reporter from state broadcaster CGTN who used to work in the U.S., wrote on the popular Chinese social-media site Weibo.

For other countries, however, the attempt on Trump was a reminder not of American exceptionalism or decline, but as a country like any other that suffers occasional spasms of political violence. In May, Slovak Prime Minister Robert Fico was nearly killed in a shooting, and in January, the head of South Korea’s left-leaning opposition party, Lee Jae-myung, was stabbed in the neck. Lee, who survived, wished Trump a speedy recovery in a Sunday post on X.

In Brazil, several hundred supporters of former President Jair Bolsonaro, who suffered an assassination attempt on the campaign trail in 2018 before winning the election, gathered on São Paulo’s main avenue Sunday to show their solidarity with Trump, a close ally of the conservative leader. “Long live Trump!" demonstrators yelled.

Many outside the U.S. will be watching closely whether the former American president will use the moment to try to start to bridge the partisan divide or double-down on division.

“It’s possible that Trump keeps emphasizing polarization and confrontation in U.S. politics," said François Heisbourg, special adviser at the Paris-based Foundation for Strategic Research. “It’s also possible he emphasizes national unity…If he does, then he could be headed for a landslide victory." Either way, he said, Europe should plan for a Trump re-election.

A possible return of Trump to the White House would mean different things to different countries. Some countries like Russia and Israel could welcome a second Trump presidency, at least initially, while many European countries, especially Ukraine, are concerned that Trump is less committed to checking an aggressive Russia and will weaken NATO, the trans-Atlantic defense alliance. Trump’s trade policies, especially promised tariffs on foreign goods, worry China, Mexico and Europe.

But the recent events in the U.S. have added to concerns that go beyond which candidate wins. Regardless of which party is in power, the U.S. has become far more protectionist in recent years and wary of foreign entanglements. Divisions within American politics are also constraining its ability to deliver on the global stage, from security to trade, according to some political analysts.

“There is deep concern about whether America can continue to lead, build partnerships and alliances," said Leslie Vinjamuri, director of the U.S. and Americas program at Chatham House, a think tank in London. “Even under a democratic administration there is so much constraint domestically because of dysfunctional, polarized and partisan politics, that even if a president means well, he will have trouble delivering."

For Ukrainian President Volodymyr Zelensky, for instance, any result in the U.S. election comes with risk. For two years, frustration toward the Biden administration has been growing in Kyiv.

Officials, soldiers and civilians alike say that aid from the U.S. comes too little and too late—just enough to keep Ukrainian forces from losing the war, but not enough to allow them to reclaim the 20% of the country that Moscow currently occupies.

Biden, wary of sparking a direct conflict with Moscow, has delayed for months—or, in some cases, years—before agreeing to send new weapons systems to Ukraine. Officials say the delays have allowed the Russians to fortify their positions, making the work of recapturing occupied territory far harder than it would have been had the weapons come earlier.

Trump, meanwhile, has promised to end the war through peace negotiations and criticized U.S. spending on aid for Ukraine. As a result, there is widespread concern among Ukrainians that if he is elected, it would mean the end of large-scale assistance from the U.S.

In a recent interview with Bloomberg News, Zelensky called on Trump to offer specifics about how he might change U.S. policy toward Ukraine.

“I’d like to understand, what does it mean to finish the war fast?" Zelensky said. “Because if there are risks to Ukraine’s independence, there are risks that we will lose statehood, we want to be prepared for this. We want to understand whether in November we will have the powerful support of the U.S., or we’ll be alone."

Germany’s government expects U.S. pressure on Europe to increase its military spending to intensify regardless of the election outcome. Recent efforts by Berlin to boost military spending and diversify trade away from China have in part been taken in anticipation of U.S. pressure.

Thomas Silberhorn, a member of parliament for the opposition conservative party, has been keeping in close contact with Republican lawmakers and will attend the party’s convention in Milwaukee this week. Silberhorn expects the broad outlines of U.S. foreign policy to remain constant whether Trump or Biden is re-elected. “You must differentiate between the election campaign, in all its brutality, and realpolitik," he said.

Across Europe, the recent events will underscore an argument that the continent can no longer afford to base its future security needs around the outcome of tight and increasingly volatile U.S. elections. French President Emmanuel Macron, has long championed the idea that Europe needs to develop “strategic autonomy" from the U.S. and other great military powers by banding together militarily to buy weapons and develop the continent’s defense industry.

Yet with political turmoil of its own in some of its biggest countries, including France and Germany, a sluggish economy and high debt loads, policymakers and analysts warn it could take years for Europe to offer a significant military deterrence to Russia.

“NATO is constantly having this conversation—how to Trump-proof NATO and Europe," said Vinjamuri. “And they’ve taken some modest steps. But the reality is America is still the indispensable partner."

For China, the Biden administration has kept in place and in some cases even expanded Trump’s tough-on-China economic policies. Yet Biden has also been far less outspoken on China than Trump, and Chinese officials worry that Trump will deepen America’s protectionist turn and introduce a period of far greater uncertainty in bilateral relations.

Mexico is also worried, given the U.S.-Mexico-Canada free trade agreement is scheduled for review in 2026. The last time Trump was in office, the U.S. threatened to impose tariffs of up to 25% on Mexican goods if the government didn’t stop tens of thousands of migrants from reaching the border. The government quickly deployed thousands of soldiers to do so.

“Trump represents an enormous menace, a huge risk," to President-elect Claudia Scheinbaum, Mexico’s first female president, said Jorge Castañeda, a former Mexican foreign minister.

Senior Mexican officials who negotiated with the Trump administration are worried about aggressive security policies targeting Mexico’s powerful drug gangs involved in the smuggling of fentanyl and migrants. House Republicans have broached the idea of using the U.S. military against Mexican organized crime groups.

Mexican officials also expect increased deportations of Mexican migrants and the dismantling of current bilateral strategies that deal with illegal border crossings.

Georgi Kantchev, Laurence Norman and José de Córdoba contributed to this article.

Write to David Luhnow at david.luhnow@wsj.com and Ian Lovett at ian.lovett@wsj.com