It is a disproportionate and unnecessary amount.
I don’t buy the domino theory so often used to support Ukraine. Yes, if we had allowed Putin to invade Ukraine at little cost, he might have thought of venturing further. But, right now, he would happily settle for 20% of Ukraine, at least some of which is more Russian than Ukrainian in terms of language and culture.
The great powers (the U.S and China) may need a more global view, but we don’t, especially if Europe won’t come along for the ride. The nations who should be investing a lot more are Germany (especially) and Poland, not the UK.
I find the grandstanding of the establishment over Ukraine quite nauseating when so many are dying here through lack of basic medical care and schools are falling apart. We might still be a rich (ish) country on paper, but that is because of the super wealthy. On a median income basis, we are really quite average.
We should pay our fair share on Ukraine, but no more.