It’s a who’s who of world leaders, diplomats, and top military officials, as the Munich Security Conference is getting underway

This time around it is happening against a backdrop of Europe’s first war in decades, and much of the attention will be on Ukraine.

But all the NATO support for Kyiv has given many of these Western military a stark reminder of global security challenges.

And there are new fears on the eve of this conference about U.S. Arms stockpiles.

General Mark Milley, the most senior U.S. officer, has said the Pentagon is now reviewing its weapons stockpiles and may need to boost military spending after seeing how quickly ammunition has been used during the war in Ukraine.

For weeks, Ukrainian counterparts have been saying they’re appreciative of western donations — but they’re increasingly pleading for more, saying that the Russian firefight is causing them to burn through it.

U.S. military planners have taken stock and say the return of 20th Century ground warfare tactics in Europe is forcing them to reconsider assumptions made in recent decades that retooled capabilities for counter-terrorism and irregular combat.

But ammunition does not come cheap.

Any review may result in an increase of the U.S. military’s $817 billion annual budget.

Other NATO allies are also considering what they have in their arsenals.