As already demonstrated US allowed Ukraine to use HIMARS on targets near Kharkiv and that that did not leave to nuclear war. Why not also let Ukraine use ATACMS?

See also: https://en.wikipedia.org/wiki/China's_final_warning

Maybe the U.S. has finally come to understand that if Ukraine really is going to have a chance to win, it must be allowed to fight the war properly.

Doubt unfortunately: https://www.forbes.com/sites/davidaxe/2024/08/05/ukraine-had-a-chance-to-blow-up-russias-best-warplanes-on-the-tarmac-the-white-house-said-no-and-now-its-too-late/

Not sure why Ukraine can’t use Western to hit military targets in Russia, how is Ukraine supposed to win a war when it cannot return fire?