L ONDON — 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. But it's a major blow that threatens to remove some of the most formidable weapons in Ukraine’s battlefield arsenal, and ratchets up pressure on Kyiv to accept a peace agreement. Here’s a look at the decision and its implications. Advertisement Advertisement How much