Beyond the "war on 2% and what is included", it's more important to realize "for what" the military spendings are intended. Where the US strives for supremacy around the world, the other Nato countries (it's in its name) have the intention for trans-Atlantic support. As such, divide the US military spending by 3 or so, to get the Nato contribution itself. Of course, we have spin-offs, reallocating, etc, though still, the "other members" % contribution is largely "inline", if not better than the US one, with the 2% target, available for Nato purposes.
Whenever Trump comes up with "something", be aware, that it's just wrong, out of context, etc. Lying without statistics......