The US probably thinks that it can just wait out the Russians:
1) Liquid assets in their NWF are depleted and can only be used to fund Russia's budget deficit for approximately one year.
2) The recent drop in the price of Ural crude will reduce the ability of Russia to fund the military while keeping domestic expenditure intact. The FT article I linked estimates a 2.5% decrease in oil revenue from this, which is significant, but not catastrophic.
3) The rate of Russian advances have slowed in the past few months.
4) It's relatively cheap for the West to fund Ukraine with their economies intact, while Russia suffers.
Meanwhile, the Russians likely want to wait out the US:
1) Any land they take from Ukraine will almost certainly be ceded to them permanently in a US-negotiated deal, so a big push this year makes sense.
2) Recruitment rates in the Russian military are increasing, at a time when many western analysts forecasted a decrease. This is likely due to the government having to increase the financial incentives for joining, but it's having the desired effect.
3) Ukraine have a manpower issue that isn't going away. Ukraine's strength is in unmanned systems but that can only do so much.
If those truly are the assumptions by the two sides, I gotta say that the Russian assumptions sound far more robust than the American ones.
Ye similar to the Israeli thread I am losing a bit of time responding to posts like this. This has all been said and argued before.
Totally fine by me. But let's pick one single point: do you really think the Russians would be willing to split the minerals and rare earths plundered from Ukrainian soil equally with the US? No fucking way.