A French Cayman helicopter flies low over a lush Transylvanian valley, dropping three soldiers onto the grass. The hills erupt with the boom of Caesar cannons and Leclerc battle tanks under NATO command.

The wargame in November offered a glimpse of the alliance¡¯s likely future as President Donald Trump reduces U.S. deployments in Europe. In the natural defensive line of the Carpathian mountains, a full-brigade level deployment of European soldiers under French command was defending the continent largely without the U.S.

The urgency of those preparations will be underlined this week as Washington deepens outreach to Russia with Steve Witkoff¡¯s trip to Moscow. As the White House pushes for an end to the war in Ukraine, its threats last month to shut off remaining military support for Kyiv raised the possibility of European powers having to defend Ukraine, and perhaps even the rest of their eastern frontier, with limited U.S. backing.