The Tiger Team, as the group is known, is also examining responses if Mr. Putin reaches into NATO territory to attack convoys bringing weapons and aid to Ukraine, according to several officials involved in the process. Meeting three times a week, in classified sessions, the team is also looking at responses if Russia seeks to extend the war to neighboring nations, including Moldova and Georgia, and how to prepare European countries for the refugees flowing in on a scale not seen in decades…

One major issue the Tiger Team is looking at is the threshold that could prompt the alliance to use military force in Ukraine. Mr. Biden has made clear that he is enormously reluctant to to do so, fearing that direct confrontation with Russia could escalate the conflict beyond control. “That’s World War III,” he noted recently.

A second team of officials, also created by Mr. Sullivan’s Feb. 28 memo, is looking at long-term opportunities for the United States to improve its geopolitical position as a result of Mr. Putin’s invasion. Inside the White House, it has become an article of faith that the Russian leader made a huge strategic error — one that will diminish Russia’s standing, cripple its economy and alienate potential allies for years. But it is early in the conflict, other officials caution, and that conclusion may prove premature.