You jest, but if you've ever seen a wounded animal fighting like mad for survival, I wouldn't be so confident that won't be the exact same things that's going to happen.
You don't have to look into the animal kingdom, history works too. No ruling empire has fallen silently and without conflict. Changing the world order always included an aggressive transfer of power
The British Empire dismantling wasn't exactly peaceful, but it could have been much worse. Next to India, everything else becomes a rounding error.
It was mostly peaceful in itself. There was a lot of conflict that followed in the wake of it as borders and power structures were settled. Just in South Asia we had the partition of India, the secession of Bangladesh from Pakistan, the Sri Lankan civil war, and various smaller separatist conflicts.
Not to mention the whole Middle East mess is due to the British on how they drew the borders when they left
In the case of my country, USA, we are the ones wounding ourselves. We made the conscious choice to elect a government that prefers isolationism to economic competition, and which rejected near-peer military preparedness in favor of more deadlock wars with third world middle east countries. It’s not like we were somehow victimized by the EU.