And it doesn’t necessarily have to be a physical war. For example right now there are a couple of cultural wars going on in the west - left vs right and Islam vs the west. They’re mostly being fought using propaganda, moralizing (guilting and shaming), and 1984 tactics.
The right could easily trounce the left in an all out physical war, but it doesn’t have the will. Similarly the west could rout the Islamists, but it also lacks the will.
Who will win these culture wars remains to be seen.
Yes, political will is essential! The Japanese gave us political will when they attacked Pearl Harbor (”awoke a sleeping giant”).
Hopefully the lessons of the demise of European culture will help us prevail over the scourge of Islam, but we were set back at least half a generation when our own Bush 43 mislabeled it “the religion of peace” right after 9/11.