NATO has no problems with unstable democracies and high levels of corruption. It was founded by the US...

More likely, Ukraine after the war will be a massively destroyed country, with widespread poverty and a constant need for western powers to pour money into - and that breeds corruption. The only way forward - should they survive as a nationstate - would be some kind of grotesquely enlarged Marshall Plan - they would become in the 21th century that what Germany was between 1946 and 1990: A military bridgehead and designated battlefield should Russia get another taste for war, with modest economic growth.

The level of destruction happening in Ukraine now is, while still terrible, an order of magnitude less severe than what happened in large parts of Europe during WW2. Many countries had around 10% of the population killed, and for those involved in the fighting, a large fraction where men in their most productive age.

Still, most countries had rebuilt their economy to pre-war levels before 1955, and in many cases around 1950.

Given the very small size of Ukraine's economy, reaching their pre-war level will not take very much. Should they, as I predict, come out of the war as a united nation, able to get rid of most of the corruption, they may be able to massively outperform their pre-war gdp fairly quickly.

If they return to pre-war levels of corruption, no amount of economic aid will bring their economy to western levels.

Ukraine can be paid war reparations with the money confiscated from Russia, including Russian reserves. It might actually boost their economy compared to pre-war situation.

Don't worry, that money is gone. It's already in the coffers of western oligarch-equivalents and shareholders. Did you think all that military hardware we've sent them grew on trees?

There’s a lot more money to confiscate from Russia.