Joe Biden is taking last-minute measures to support Ukraine before leaving things to Donald Trump.
While Putin telegraphed an evolution of Russia's nuclear doctrine back in September, it's reasonable to assume Moscow's written version of the change was sped up by Biden's ATACMS move.
North Korean troops have joined Russia on the battlefield, Ukraine is striking deep into Russian territory with US-provided weapons, and the Kremlin is yet again making nuclear threats.
The relaxation of the restrictions on US weapons may have come too late to alter the course of the conflict, but it could help Ukraine defend its foothold in Kursk.