People familiar with the discussions say one option under initial consideration is to include national spending to improve a country’s resilience to attacks on vital infrastructure, or hybrid attacks that aim to undermine public opinion and trust in democratic institutions.
Another possibility is letting countries include investments that are vital to military operations, such as transportation infrastructure that militaries rely on. NATO includes some military infrastructure in its spending total, but not civilian infrastructure that might be used by militaries in wartime.
I mean they are starting too but mainly because they no longer view the U.S. as a reliable military ally.
It would not surprise me if a new organization is created for defense against Russia, China and the U.S.
Trivia: check which countries count military pensions as their defense expenditure.