It should have ended in April '22 when Russia and Ukraine almost reached a working peace deal. This is already a proven fact by multiple sources now and even western reporting back then. At that point in time the combined EU(Scholtz), Boris(UK) and presumably the US with their blessing decided that they could use this war as a "cheap" way to fight a proxy war against Russia and that Russia would not escalate if Ukraine did not cross certain red lines(e.g missile strikes on Russian soil).

Arming Ukraine is cheap compared to the far higher price of Russian victory- Atlantic council

Concerns over mounting expenses are understandable but shortsighted. While Ukraine has so far received hundreds of billions of dollars in military aid, this figure pales into relative insignificance when compared to the far higher price the international community will have to pay in the event of a Russian victory.

A wide range of Western politicians and commentators have already made the case for the cost-effectiveness of funding the Ukrainian war effort, with many noting the dramatic reduction in Russia’s military potential as a result of crippling losses suffered in Ukraine. In May 2023, US Senator Lindsey Graham described American military aid to Ukraine as “the best money we’ve ever spent.”

US Senate Minority Leader Mitch McConnell has recently echoed Senator Graham’s sentiments. “No Americans are getting killed in Ukraine. We’re rebuilding our industrial base. The Ukrainians are destroying the army of one of our biggest rivals. I have a hard time finding anything wrong with that,” he commented on October 20.

McConnell’s arguments are certainly persuasive. However, in order to fully appreciate the true value of continued support for Ukraine, it is necessary to contemplate what would happen if Western military aid came to an end and Vladimir Putin succeeded in subjugating the country.

Finaly the problem is that Ukraine is governed and filled with hardcore Nazis that will accept nothing but genocide and ethnic cleansing of Russians in Donbass and Crimea. Why? Beyond the obvious nazism is the fact that Ukrainian "nationalism" is a myth based on nothing but extremely cherry picked history that intersects with actual Nazis all the way back from WW2 and historically the US looked for the opportunity to support this movement against the USSR and now they're lucky they can use this against Russia.

Therefore throughout late '22 and '23 they promised that they could retake territory if they were given proper NATO equipment and training.

Meanwhile NATO naturaly believes their own BS about white supremacy so of course they thought 6 months of training some clueless Ukrainian teenagers plus a handful of German tanks made in 1985 was all it takes to beat Russia.

As it stands now were are in the middle area where some of the western leaders can see the eventual Ukrainian failure after the offensive but the UK and EU remain committed to Ukraine for political reasons.

For Germany/France specifically it is their only excuse for destroying the economy. The US destroyed nordstream and they still claim Russia unilaterally stopped the gas supply. They've picked this hill to die on because there is nowhere else to go other than to admit defeat and that is political suicide.