"Would you have preferred to have lost the "Magic" code breaking advantage, and hence lost (among many battles) the Battle of Midway and WW2 in the Pacific?"
That is a BS argument. How would Japanese spies find out about MAGIC when it wasn't even known to military commands below the theater level? Why couldn't the U.S. have been as successful at turning Japanese agents into double agents as the British were with the Germans?
The Battle of Midway was fought in early June 1942. The legislation enabling relocation of Japanese-Americans was passed on Feb. 19, 1942. How many of them were actually relocated before Midway occurred? It's not like the U.S. had the relocation camps prepared and ready upon enactment of the relocatin statute.
As far as compromising MAGIC, the Japanese had to know something was amiss when the U.S. Navy was able to conveniently have all of its available combat power on location to fight the Battle of the Coral Sea and then Midway without sending any significant forces to react to the Japanese diversionary attacks. The enemy guessing correctly twice in a row where to position aircraft carriers in the expanse of the Pacific Ocean would arouse suspicion in even the least competent communications and intelligence officers.
Oddly enough, the Japanese never seemed to figure it out. Just as the Germans failed to realize that their codes had been broken.
You totally miss the point. (Not surprising, why do I bother?)
If we had gone out and had the FBI arrest the exact 100s of west coast Japanese spies, that would have blown the secret that we had broken the Magic / Purple codes. This secret was so closely held and ultravaluable to the success of our war effort that even Truman did not know of it.
Compare this to the German bombing of Coventry. Churchill knew from MK Ultra the exact time of Coventry's bombing. If he had ordered fighters to be shifted from the south to meet the Nazi bombers, the secret of the broken codes would have been put at risk. Coventry was bombed, and many Brits died.
Would you condemn Churchill for his "inhumane" decision to intentionally allow thousands of Brits to die? Of course not. This must be put into the context of the strategic picture of fighting a world war.
Just so with the Magic codes, and the Japanese relocation.
Hey, it beat being blown to bits in Coventry.