The entire point of gray zone warfare is that it makes it nearly impossible to justify a kinetic response.

The US uses tit for tat game theory to minimize escalation. It requires the use of proportional responses.

When it comes to gray zone warfare, it's difficult to gauge a proportional response. The US has mostly responded with sanctions and continuing to arm and remove limitations on Ukraine. They are also feeding Ukraine intelligence, but that's less public for obvious reasons.

NATO is also preparing for a large-scale conflict. They just added many members and now need to setup logistics and integration with the new members. They have publicly stated they are modifying their doctrine and working with civilian companies to handle a rapid mobilization of 800,000 troops on the eastern front.

NATO defense contractors are also prepping to transition to burst production capabilities because their production switched to more of a trickle during the war on terror. Creating new facilities and securing large supply chains is difficult and time gated.

Hopefully, NATOs posturing will be the deterance needed to prevent this cold war from igniting. "If you want peace, prepare for war."