The race is on.

As columns of Russian troops began pouring into Ukraine nearly two months ago, the United States and its allies started supplying Kyiv with weapons and equipment for what many expected to be a short war: sniper rifles, helmets, medical kits, encrypted communications, lots of bullets and the portable, shoulder-held Stinger and Javelin missiles that quickly became icons of the conflict.

Defying the odds, Ukraine held on to its capital and pushed Russia from the north. Now, as the Kremlin switches gears and begins a concerted effort to capture eastern Ukraine, Washington and its allies are pivoting as well, scrambling to supply Ukraine with bigger and more advanced weapons to defend itself in a grinding war.