A Biden Doctrine Starts To Take Shape, theamericanconservative.com

Andrew Bacevich, president of the Quincy Institute for Responsible Statecraft

[…] Present-day U.S. practice combines elements of a disastrous Bush Doctrine and a deeply flawed Obama Doctrine. The former, conceived in the wake of 9/11, asserts a prerogative of waging preventive war to overthrow regimes that the United States deems intolerable. The latter finds expression in a campaign of assassinations planned, authorized, and executed in secret.

The Bush Doctrine yielded a legacy of protracted, exhausting, and very costly armed conflicts. The Obama Doctrine yielded a low-level war of attrition, employing airstrikes and small contingents of special operations forces. Both had presidents exercising broad extra-constitutional powers, with minimal accountability. […]
Trump’s critics frequently charge him with abandoning norms. Yet in matters relating to the use of force, it was Bush and Obama who cast aside well-established norms. Biden’s task is to reconstitute them.Devising a sensible doctrine for the use of force should begin with a realistic appreciation of what force can and cannot do. Here the American preference for the language of liberation poses a problem. Only rarely does liberation provide a legitimate rationale for war. In practice, liberation entails nation-building, not only ousting objectionable regimes, but installing something better in their place.