US President Donald Trump has gone all in with his effort to strongarm Kyiv into peace negotiations with Russia, suspending US military aid to Ukraine with immediate effect. The move has sent shockwaves through the Western world and left Ukraine and its allies scrambling.

The directive, which takes effect immediately, affects more than $1 billion in arms and ammunition in the pipelines and on order.

The U.S. has been Ukraine’s biggest military backer since Russia’s full-scale invasion began three years ago. The suspension of that aid by the Trump administration doesn’t mean Ukraine’s defenses will quickly collapse.