Zelensky has offered to take Ukraine neutral. Which is precisely what is going to happen if Putin does what he said he would do in his speech. Putin can't occupy Ukraine or go after other countries without massively increasing his armies. And that requires money he doesn't have.
Hopefully he demilitarizes Ukraine then pulls out. The US has shown that it's relatively easier for a larger power to win a few battles, but retaining control over years costs trillions.
Zelensky could have stopped all this easily as recently as a few weeks ago. The question is why he didn't?