Great post. The success of the Roman Empire - and all other empires resulted from conquest and submission.
The current state of Europe and soon to be the USA, is that new citizens/immigrants are neither the conquered or the submissive. They have no requirement to assimilate to the culture(s) they join, Europe or USA.
Ergo........Italy no longer comprises Italians, England (Britain) no longer has Englishmen to send to war (or Irish, Welsh & Scots) - the French just added more recalcitrants to their numbers. The Spanish only talk the talk and the Greeks are keeping a low profile. Turkey is Islamic.
There's no going back to the 18th or 19th Century Europe for Western nationalism. It's history.
Muslims have guns & do travel.
sp
BTTT