Current NATO spending according to Wikipedia is a total of 1.036 trillion. You can see that here:
https://en.wikipedia.org/wiki/Member_states_of_NATO?wprov=sfti1#Military_expenditures
EDIT: Spending as of 2023 is 1.1 trillion:
https://www.nato.int/nato_static_fl2014/assets/pdf/2023/7/pdf/230707-def-exp-2023-en.pdf
This represents 2.5% of combined GDP, which is 49.8 trillion in total.
Resolution criteria are that NATO spending surpasses 2 trillion US Dollars for at least one year before the END of 2028.
If you have any information that might help inform peoples decisions, please post in the comments!
1.47 trillion for 2024 https://www.statista.com/statistics/1293301/combined-defense-expenditures-nato/
@EvanDaniel Nominal. Just makes it simpler, and I think either way the amount of time between now and then is nowhere near long enough for the nominal amount to significantly change without real change