It's not so much a matter of spending levels but what you get for that spending. Since the end of the Cold War, most European countries have treated their militaries as essentially government jobs programs. The money was thrown away to hold down unemployment, and any combat effectiveness was incidental. The current crisis is finally forcing a change in that mentality but it will take years to turn the situation around.

In nominal terms "we outspend them" is true, but it misses the forest for the trees.

Nominal spend is the wrong yardstick when one side builds at home for a fraction of the cost; Russian labour, steel and energy are far cheaper at the point of use, which is why PPP estimates put their real military output roughly level with the whole of Europe combined.

And spend isn't the binding constraint anyway: it's production. A budget line is not a full magazine, and we've spent years throwing our stockpiles into Ukraine while letting our shell and propellant lines wither instead of refilling them.

"We don't need to catch up" assumes the money on the page is already steel in the field. It isn't.