The president of the United States has no more solemn duty than defending the nation. And with conflicts raging in Ukraine and the Middle East, tensions brewing in the Indo-Pacific, and growing alignment among America’s rivals and adversaries, the stakes in the election for U.S. national security are high.
Against this turbulent backdrop, former President Donald Trump regularly presents himself as an indispensable peacemaker and claims his return to the Oval Office is the only way to “prevent World War III.” Voters must therefore ask themselves a core question: Does Trump have what it takes to be commander in chief at this perilous moment? The answer is clearly no.
To be fair, Trump’s Pentagon—with Secretaries Jim Mattis and Mark Esper at the helm—usefully reoriented America’s national defense strategy to prioritize great power competition with China and Russia, after a generation of focusing primarily on rogue states and terrorists. Working with bipartisan support on Capitol Hill, the Trump administration secured additional necessary resources for this new era of great-power rivalry.
A souvenir shopkeeper displays Matryoshka dolls featuring Russian President Vladimir Putin and Donald Trump, on Dec. 3, 2019 in Moscow, Russia.
Misha Friedman/Getty Images
It is notable, however, that the architects of Trump’s defense strategy profoundly disagreed with their boss. Mattis, one of the most respected Marine Corps generals in history, resigned in December 2018 citing irreconcilable differences with Trump over the treatment of U.S. allies. After leaving office, Mattis described Trump as a threat to the Constitution. Esper was summarily fired by Trump in 2020 for refusing to support the deployment of U.S. troops against domestic protesters. Ominously, Esper has warned that Trump’s renewed threats to use the U.S. military against the “enemy from within” if he returns as commander in chief must be taken seriously.
There is little doubt a second Trump term would be worse in this regard. Trump is unlikely to hire people with the integrity and stature of Mattis and Esper given his stated desire to surround himself with senior Pentagon officials who enable rather than constrain his worst impulses.
And make no mistake: the national security implications of those impulses could be profound. In a dangerous world, America needs a commander in chief that stands by our allies, stands up to our enemies—and has the judgement and moral compass to know the difference. And yet, as president, Trump consistently demonstrated the opposite.
America’s allies and partners represent a clear advantage over China, Russia, and other challengers. Yet, during his first term, Trump repeatedly denigrated our allies. He threatened to withdraw from NATO, the world’s greatest military alliance and a cornerstone of American security, because too many members were “delinquent” in paying their bills. He came close to abandoning allies like Germany and South Korea over trade disputes, only to be talked out of it, or otherwise thwarted, by senior advisers who understood the dire geopolitical consequences of doing so.
On the 2024 campaign trail, Trump continues to call into question his willingness to defend NATO—even going so far as to say he would encourage Russia to “do whatever the hell they want” if our allies don’t pay up. Trump has questioned U.S. support for Ukraine as it defends itself against Russian aggression, and has suggested he might not honor America’s bipartisan support for Taiwan if it fails to pay the United States for its defense against China.
Urging our allies to spend more on defense makes sense. But serially treating U.S. security commitments and partnerships as if they are protection rackets undermines deterrence and makes war more likely.
This problem has been compounded by Trump’s dangerous inconsistency toward our rivals and adversaries. As president, Trump was fond of tough talk on China—only to soften his position in response to flattery and empty promises from Chinese President Xi Jinping. On Russia, he regularly sided with Russian President Vladimir Putin and infamously conditioned security assistance to Ukraine on political favors (earning Trump his first impeachment). As North Korea advanced its nuclear and long-range missile programs, Trump vacillated between “fire and fury” threats to start a nuclear war on the Korean Peninsula and exchanging love letters with North Korean dictator Kim Jong Un. And on Iran, he authorized the strike against Qasem Soleimani—the commander of the paramilitary Quds Force—but then failed to act when Iran responded by launching ballistic missiles that injured scores of U.S. troops. He also ditched the Iran nuclear deal without a viable replacement, freeing Iran to resume its dangerous nuclear progress while doing little to curtail Tehran’s support for terrorism and proxies like Hamas, Hezbollah, and the Houthis.
Ambiguity can aid deterrence. Incoherence cannot.
Given this record, it is hard to imagine Trump bringing peace or calm to the world if he returns to the White House. More likely, a second Trump term—unencumbered by sensible advisers and emboldened by an election victory—would unleash his worst, and most chaotic, instincts on the world stage. That is hardly a risk America can afford.
Colin H. Kahl is the Steven C. Házy Senior Fellow at Stanford University’s Center for International Security and Cooperation, the Sydney Stein, Jr. Scholar in Residence at the Brookings Institution, and a former Under Secretary of Defense for Policy.
Michael O’Hanlon is the Philip H. Knight Chair in Defense and Strategy at the Brookings Institution.
The views expressed in this article are the writers’ own.
