I know we all wish more was being done. But, what would have America do? Our allies in NATO do not want a war and America should not be the one to trigger the alliance agrreement – i.e. conflict on any NATO member's soil triggers a full response from ALL the alliance members (in other words, triggers active war declarations from every NATO country, committing boots on the ground and bodies on the line. The Biden administration rallied the world and is holding it together in opposition, offering everything short of boots on the ground – even pushing Europe and the UK to impose a broad oil embargo on Russia, something that would be a serious long-term detriment to the EU and UK. There really are few options remaining except head-to-head war – a war no one can win.
As you said, this is really Putin's war. But, short of the international crime of assassinating a world leader, how do you propose America remove Putin from power? Does America even have that right? Isn't that very regime destruction Putin's agenda in Ukraine?