WASHINGTON — A few thousand American troops to train the Afghan Army. A single-minded focus on counterterrorism, with C.I.A. drones and Special Operations units hunting down terrorists. A healthy skepticism of Pakistan as an abettor of Islamic extremism. And an explicit repudiation of grand plans to nurture a Jeffersonian democracy in Central Asia.

These are the hallmarks of the Afghanistan strategy President Trump set out on Monday night. They are also the hallmarks of the strategy former Vice President Joseph R. Biden Jr. tried unsuccessfully to sell to President Barack Obama in the fall of 2009.

The parallels between Mr. Trump’s and Mr. Biden’s plans provided a sense of irony — even comfort — for the Washington foreign policy establishment, which has felt deeply alienated during this presidency, watching Mr. Trump’s unorthodox statecraft with a mix of horror and dismay.

But the similarities are more than a historical footnote: Mr. Biden has talked about running for president in 2020, and he would start off as a front-runner in a splintered Democratic field. If Mr. Biden were to run, he would no doubt make his foreign policy credentials, and Mr. Trump’s haphazard debut on the global stage, a major theme of his campaign.