While calling for a “true European army,” Macron said something that was guaranteed to grate on the American president: “We have to protect ourselves with respect to China, Russia and even the United States of America.” And then he went on to rub more salt in the wound by asserting: “We must have a Europe that can defend itself on its own without relying only on the United States.”

It was almost an affront, if one thinks that the United States has intervened twice to save Europe, and that under no circumstances it would stand idly by if Russia or any other country would suddenly attack the old continent. Trump wasted no time in pushing back, by repeating what he thinks about the European allies, namely that they are welching on the U.S. by not paying their full share of NATO expenditures.

The main offshoot of Macron’s sharp reproof is that it carries water to Trump’s political message to his base that is hardly enamored of multilateralism, devotion to alliances and far-flung commitments in the world. President Trump has not threatened to leave NATO but has hinted at a hard look in that regard. The European allies do not seem to take him seriously, given their low regard for the fickle and disruptive behavior of the American president. Unfortunately, European-American relations have entered a critical phase and Macron’s speech reflects it.

The mano a mano of the two presidents is not about the state of international relations as seen across the ocean but rather about their foreign policies as internal matters that impact their leadership. President Macron is handicapped by the internal politics of France including the fact that, unlike Trump, he does not have the support of a party. His foreign policy is part and parcel of his strenuous effort to keep the nationalist forces at bay. The threat to his presidency by Marine Le Pen’s Front National forces him to inveigh against the sovereignist Visegrad Group in central Europe and to block the wave of migrants that afflicts neighboring Italy. Not surprisingly, Macron took aim at Trump’s recent embrace of the term “nationalism” and rejected it with the argument that “nationalism is a betrayal of patriotism.”

What this sharp dialogue between two “deaf” presidents fails to bring out is that both Americans and French are true nationalists, with the difference that Americans think of nationalism as “exceptionalism” while Trump is correct in pointing out that “there is no country more nationalist than France.”

The French National Front, founded in 1972 by Le Pen’s father, Jean-Marie Le Pen, is a far-right movement that anticipated Donald Trump’s political emergence. As for Macron, one doubts the wisdom of fighting Marine Le Pen by opposing any nationalist position in France and picking a fight with Trump by denouncing the “old demons” of nationalism that are coming back “to wreak chaos and death.” If Emmanuel Macron sounds nearly catastrophic, it is because Marine Le Pen is snapping at his heels and his approval rating is heading south.

Finally, there is more that poisons the relationship between Trump and Macron. In particular, the most recent irritant is President Trump’s decision to withdraw from the US-USSR agreement of 1987 on intermediate nuclear forces. Macron came out strongly against this decision claiming that the security of Europe is the “main victim.”

Earlier this year, the French president vainly tried to talk Trump out of withdrawing from the 2015 nuclear agreement with Iran and complained about the damage of U.S.  sanctions for European companies doing business with Iran. These events cannot but swell the dark cloud that is growing on the future of the transatlantic alliance.

As the United States seems to eschew more and more the demands of global leadership, there is talk of a return of America to some kind of isolationism, a recurring temptation in American foreign policy. There is no question that many Americans are tired of shouldering the burden of world leadership. However, the temptation of isolationism is nothing new and Donald Trump is not the first president looking to reduce foreign commitments. The French, and not just their president Macron, are justly concerned that America detaches itself from Europe while President Trump is sympathetic to petro-state monarchs and authoritarian leaders. They are not alone. It behooves both Trump and Macron to stop quibbling about payments to NATO and degrees of nationalism to preserve the solidarity of the alliance for the day when it will be tested by an unforeseen crisis.