Given that Biden is deeply ensconced in the mindset of the national-security establishment, he will automatically buy into and support whatever official enemies the Pentagon, the CIA, and the NSA proclaim are threats to "national security."
The most likely candidate is Russia. Count on the continuation of Russia's role as America's Official Enemy Number One. While everyone thought the Cold War ended long ago, not so for the U.S. national-security establishment. The Cold War was a high-cotton racket for the Pentagon, the CIA, and the NSA, and they weren't about to let it go. That's why they did everything they could to ensure that Russia remained an official enemy of the United States during the Trump administration. There is little doubt that Russia's role as Official Enemy #1 will be magnified during the Biden administration.