While it sucks, Europe has to do it. It's not threatened just by Russia anymore, but by US itself these days

Drumpf is literally every other day threatening to invade Denmark, an EU member for no reason whatsoever. It's quite insane

Also, you never know who Americans could elect next time, or time after that. Maybe someone even more unhinged.

Europe must be able to defend itself

Working towards 5% isn't really that stupid for most European countries as long as Russia is spending as much money as it can on weapons. It will only become a waste of money after the implosion of the Russian oligarchy. I am not in favor of spending that much money of things that kill stuff, but it makes total sense to continue doing that for now.

Russia's threat is real. Whether they need 5% or less could be discussed, but military spending is necessary. Plus if they're smart, that money stays in European's companies, jobs, etc.

Most european countries have embraced neo-liberalism at various paces. If they're short on money, they could tax their billionaires based on their wealth. They don't. No one does, therefore: it's a political ideology to have financial issues and cut through public services, healthcare, social support, etc.

They're scared of losing the American security guarantee and this is what it costs them to create a comparable EU guarantee.