On the same evening this week, the two major parties’ presidential candidates each gave a speech that revealed the fundamental nature of the man.

In Washington, President Biden assembled world leaders to mark the 75th anniversary of the founding of NATO, which Biden has rebuilt and expanded over the last 3½ years. “The American people know that all the progress we’ve made in the past 75 years has happened behind the shield of NATO,” the (very) elder statesman told them, in the same room where Harry S. Truman signed the treaty forming the alliance. “And the American people understand what would happen if there was no NATO: another war in Europe, American troops fighting and dying, dictators spreading chaos, economic collapse, catastrophe.”

Biden rallied his counterparts to accept nothing short of victory in Ukraine. “When this senseless war began, Ukraine was a free country,” the president said, to applause from the world leaders. “Today, it is still a free country, and the war will end with Ukraine remaining a free and independent country. Russia will not prevail.”

In Miami a few hours later, former president Donald Trump assembled supporters at his Doral golf club and ridiculed NATO partners. “I didn’t even know what the hell NATO was too much before” he became president, Trump told them. “But it didn’t take me long to figure it out, like about two minutes. And the first thing I figured out was they weren’t paying.” He repeated his boast and said he told NATO partners that if they were “delinquent” (there is no such thing in NATO, which does not collect dues), “I will not protect you from Russia.”

Thus did Trump celebrate his willingness to squander the deterrence that has kept the peace for decades, and instead to abandon allies to the tender mercies of Vladimir Putin, who just bombed a children’s hospital in Ukraine. Trump says he’ll make Ukraine “settle” with the invading Russians, a surrender that Biden would never allow.

This is exactly what the presidential campaign should be about at this perilous moment: the choice between strong American leadership and appeasement, between democracy and dictatorship.

But this is no longer what the campaign is about. The heavy-handed attempt to force Biden to quit the race after his disastrous debate has, predictably, backfired. Biden has dug in, pitting “elites” against the people. Democrats are fighting among themselves. And Republicans can hardly believe their good fortune, as they portray Biden as a zombie - with no good answer to their attacks.

Trump himself made Biden’s purported feeblemindedness - always an element of his stump speech - the dominant theme. “They all knew this guy was grossly incompetent, and every Democrat in the House and the Senate was in on it,” he alleged.

The former president’s remarks could be described as bizarre. He remarked on the looks of a “beautiful waitress” and referred to Chris Christie as a “fat pig.” Gangster Al Capone was a “very nice gentleman, very fine man,” and fictitious serial killer Hannibal Lecter “was a lovely man.” Tourists who go to see the Jefferson Memorial or the Washington Monument “end up getting shot, mugged, raped.” Less amusingly, he said those who attacked the Capitol on Jan. 6, 2021, were “hostages, unfairly imprisoned,” who “should be out soon” because of the Supreme Court. And he announced that “we have nuclear submarines and five warships in Cuba.” Was Trump publicly divulging the location of U.S. nuclear assets? Or when he said “we,” did he mean Russia? Neither one was a good look.

Alas, this is what the rest of the campaign is likely to be about if Biden remains in the race. Some of this is the fault of anxious Democrats rushing to force him from the race, which has understandably caused Biden to resist. Some is the fault of my colleagues in the news media, breathlessly tallying the (relatively few) Democratic lawmakers who have publicly called for him to quit. But Biden created this situation when his stunning debate collapse left serious and legitimate doubts about his fitness.

As president, Biden has invariably acted in the best interest of the country. I suspect that, if he sees more data coming in showing that he no longer can beat Trump, he will graciously bow out.

In a news conference Thursday night after the NATO summit, he suggested he would reconsider his candidacy if his advisers “came back and said, ‘there’s no way you can win,’” then added: “No poll says that.”

Biden was solid and clear during the session, discussing foreign policy in fluid detail. But any benefit from that may have been lost when he said “Vice President Trump” when he meant “Vice President Harris,” after earlier introducing Ukraine’s Volodymyr Zelensky as “President Putin.” Predictably, almost all of the questioners asked him about his mental acuity and the wisdom of remaining in the race.

At the moment, it’s difficult to see the national discussion shifting back to where it should be: on Trump’s fitness for office.