The agreement is actually pretty much 3.5%, the amount that must be directly spent, and the target deadline is 2035. The rest, 1.5%, is for defense related expenditures, but the definition is quite broad. Broad enough that I image much of existing gov't spend can be reclassified into this 1.5%. 3.5% is still an ambitious target though, but with such a long deadline, countries may drag their feet to meet this target.What is this insanity? Are these countries actually serious about a 5% GDP commitment on military spending? How? Why? Are they trying to bankrupt their countries?
The saddest thing about all this is that I doubt that any of these countries will get a significantly stronger military out of it. The only exception might be Poland since at least they seem to be serious about increasing their capabilities. For everyone else, the military budget isn't the reason why their militaries aren't stronger. The main problem is that their military structures are rotten and increasing the budget doesn't do a damned thing to fix their actual problems.