Those who ignore tragic history, will eventually see that tragedy happen again; that s my spin on a very true, time honored axiom about history, which will expand, unfold and reveal my answer to this question.
When Japan s attack on Pearl Harbor forced us to enter World War 2, the United States had thousands of Japanese born residents, naturalized and those pending legal citizenship. We knew the potential ease of enemy Japanese loyal combatants, hiding in plain sight IF we didn t take the action we may not be proudest of having done.......but it DID spare the U.S. from surprise "terror cell" attacks, while we sent men to fight ( and die, in thousands of incidents ) for America in WW 2.
We built Japanese Interment camps in vast remote locations along the Western middle America areas---and sent Japanese Americans to live there. And these Interment camps were way far more clean, decent and humane---than any existent felony prison in the U.S.
And yes: We did in fact, find within those Interment Camps, A LOT of Japanese Imperial loyalists, who had direct planned orders to attack America WITHIN our country, AFTER Pearl Harbor, in the name of the Japanese Empire!! By the way, we returned them to Japan after the epic Surrender ceremony, ending World War 2; they were in way far better physical / mental condition than any of OUR surviving troops, returning home from hellish years in Japan's POW camps.
Cast shame on our decision to build those Interment Camps---but they DID SAVE thousands of AMERICANS from permanent injury and/or death, from domestic based attacks by Japanese Imperial loyalists, HIDING IN PLAIN SIGHT!!
Let's move on to the Vietnam War a moment......
Walk in the shoes of some U.S. Army grunt, sweating off pounds, walking down a village street in humid South Vietnam, during that war s heydey. Now: look around and pick out the North Vietnamese loyalist enemy. Good luck with that, because many U.S. military servicemen couldn't distinguish innocent civilian from North VC; their names are etched on the Vietnam Memorial.
The point here is no one can really tell patriot from enemy, once the army uniforms are cast aside. Ok...let's move a tad forward a couple of decades.......just before 9/11.......
America became LIBERALLY OPEN to visiting "college students" from Mid East countries; 18 of them were those suicide attackers who pulled off 9/11--we never saw them coming, till it was too late. Yet we continued to ignore past history---and kept allowing them to flood across U.S. borders into America.
Let s go back to WW 2. Question: How many Japanese Imperial attacks INSIDE the U.S. happened AFTER the Pearl Harbor attack? How many such attacks during or after WW2?