He pretty much has to. From what I read in Jim Mattis's recent book, Obama and Trump both significantly damaged the credibility of the US military among allied

He pretty much has to. From what I read in Jim Mattis's recent book, Obama and Trump both significantly damaged the credibility of the US military among allied nations. If Biden lets the USA appear weak and unwilling to push back against other super powers, then smaller nations are likely to change their allegiances to whoever they think will keep them safe.