Earlier quoted context omitted.
and the contract says nothing about what you claim. PS. : the spending goal is in the future: 2025. It‘s also a political goal, not a contract. And the current data can be seen here: https://www.nato.int/nato_static_fl2014/assets/pdf/pdf_2019_... Look at the numbers, they are vastly different from what you claim.
"Look at the numbers, they are vastly different from what you claim. " They are "vastly different" because most countries don't share their fair burden. Trump may be wrong in many things, here he is right. In the PDF you provided "NATO guideline 2%" But hey, why spent it on the military? Let the US spent/fight for us.
Everything of that is wrong, There is no contract. The goal of 2% is set for 2025, not now. Currently a bunch of countries spend less than 2%.
And: large parts of the US military spending is completely unrelated to NATO.
Next you need to ask yourself if these approximate numbers make sense:
Europe minus Russia, without the US: defense spending of 350 billion USD. NATO has defense spending of 950 billion dollar. Russia: defense spending: 65 billion USD.
Europe is already outspending Russia five times. NATO is outspending Russia by 15 times.
This looks like lack of money is not the actual problem NATO has.