It's the UK we're talking about here.

To skip the currently political sensitive topics of who is helping who with what, who feels the consequences, what prices are affected because of that, let's go a bit further in the past... for example, UK taxpayers money went for bombing Iraq for the "weapons of mass destruction" when Tony Blair already knew those didn't exist.

At some point you have to ask, is it really for defense, if you're bombing someone a quarter of a planet away? Are you really protecting your people at home by doing that, and are they happy their money is being spent for that instead of eg. healthcare, education, etc.?

And the same UK taxpayer money is now being spent to ferociously defend Ukraine, and in turn European interests. That same UK taxpayer money is spent to promote freedom of the seas for global trade, whether it be the Hormuz, the Malacca Strait, the Indian Ocean, the Atlantic, the Baltic or the Horn of Africa.

Defence spending is only as good as the government that controls it, but you can't be serious if you're discounting the importance of military readiness at all times, given the world we live in.

The UK's military spending has always been much more justifiable, especially given that the country actually spends a lot on education and healthcare too (and I will argue that both of them are some of the SOTA systems in the world currently, in spite of their challenges).

You can't just skip the currently present and urgent defence requirements because they're "politically sensitive" and then go twenty years back to support your point.

But even if you want to do that, why don't you go just a couple more years further and argue that Bosnians should've been left to be genocided?