Russia must be assessing whether it wants to or is capable of spending at least another $60 billion to take Ukraine to match what the U.S. is spending, and is willing to lose at least another 250,000 soldiers, combined with the staggering 442,880 Russia has already lost in little over two years. It could be looking at losing a million soldiers or more by 2028. I can’t imagine the Russian people will think that’s worth it. Putin will be risking his own stability and life if he doesn’t capitulate and seek a negotiated settlement of the territories he currently occupies. And yet Russia views Ukraine as a breakaway republic on its border that needs to be friendly, not hostile, as integral to Russian security.
On the other hand, how long can Ukraine survive without billions in U.S. and European aid? Presumably, the current largesse will last several years unless Russia successfully bombs or assassinates Ukrainian leadership and leaves the country leaderless. Some analysts think Ukraine has little chance of surviving economically without a major rebuilding of infrastructure and strong economic ties with Europe and Russia.
Russian Empire (Wikipedia)
Teaching History's Slender Threads, Including 'What Ifs', Almosts, Alternatives and Turning Points 