What would U.S. foreign policy look like under a hypothetical Biden presidency? A lot of smart people have been diving into this. But none of us can do these predictions with high confidence. What we can do is list the factors that will determine the answer one way or the other.

First, we have the geopolitical environment. Like every president before him, Biden will try to do big things. Yet like all presidents, he will also be constrained by his environment: a competitive China; irritable Russia; overstretched military; shaky economy & strained society.

Second, personnel. The policy recs given to Biden will result in large part by the people who staff his administration. Some of these people—especially if they’ve spent decades in the U.S. fp establishment—will have strong belief systems & a set of ingrained assumptions.

Third, Biden himself. As a senator, Biden had a history of supporting U.S. intervention on moral grounds. As VP, he was actually one of the more skeptical voices in the Obama admin about what intervention could achieve. Which Biden will win out? Will it depend on the case?

Fourth (tied to No. 1 above): an earthshaking geopolitical event. G.W. Bush campaigned as somebody who believed U.S. fp needed to become more humble. Then 9/11 happened, which resulted in two wars and the Freedom Agenda. Would Biden react to a crisis in such dramatic fashion?

There are undoubtedly more factors, but IMO the four outlined above may be the most determinative.