>>513397986 (OP)
An attempt at saving face for everyone involved so that things can hopefully gracefully deescalate. If questioned in their respective countries, everyone can just mention a vague "security guarantee" as justification for various things, and including the US in the "guarantee" probably makes it easier for everyone else to just nod along.
>>513397986 (OP)
It means NATO (globohomo) and Russia (globohomo) need to increase their military spending to ensure safety (totalitarian control and more surveillance) and joint collaboration.