To many observers, Donald Trump’s open bellicosity – his threats to attack Greenland and Iran, and his recent kidnapping of Venezuela’s president, Nicolás Maduro – looks like an ideological reversal. “Donald Trump betrayed his MAGA base today [by] launching a war of choice to bring regime change in Venezuela,” tweeted Democratic congressman Ro Khanna on 3 January. The day before, former Republican representative Marjorie Taylor Greene wrote: “President Trump threatening war and sending in troops to Iran is everything we voted against in ‘24.” On 20 January, National Public Radio reported that “Trump supporters share confusion and anger over the president’s focus on Greenland”.

The sense of whiplash is understandable. As a candidate, Trump often denounced war. Now he is infatuated with it. But while Trump seems uniquely set on dismantling the postwar order in the service of his quest for global domination, there is precedent for his transformation.

Presidencies are not static. They evolve. And over the last half-century of US foreign policy, one pattern is clear: the more time passes since America’s last calamitous war, and the more presidents use military force without encountering costly resistance, the more aggressive they become. Successful wars are intoxicating; they turn doves into hawks. It happened in the decades between Vietnam and Iraq. And it is happening to Donald Trump today.

History also shows that hubris of the kind presently emanating from this White House generally ends in disaster.