In the chaotic finale of America’s 20-year war in Afghanistan, a Biden Doctrine is emerging: a foreign policy that avoids the aggressive tactics of forever wars and nation building, while uniting allies against the authoritarianism of rising powers.

President Biden began to define this doctrine on Tuesday when he declared the end of “an era of major military operations to remake other countries,” offering what he said was a better way to protect American interests around the world through diplomacy, the military’s targeted antiterrorism abilities and forceful action when necessary.

But the disordered ending to the war has laid bare the strains inherent in Mr. Biden’s foreign policy, which calls for a return to protecting human rights and promoting democracy, but only when consistent with U.S. goals. The president’s withdrawal from Afghanistan makes clear that he saw risking more American lives there as no longer in America’s national interest.