Suppose, in the Pacific, USMC 1LT Joseph McCarthy's plane had been shot down, and McCarthy was lost at sea and presumed dead, never to turn up? How would this alter politics and foreign policy in the early '50s with no Tail-gunner Joe to spearhead a broad-brush anticommunist move?
First: would there be an anticommunist push even similar to that in OTL? If there were, who would lead it (one suggestion: Indiana senator William Jenner, who was one of McCarthy's strongest supporters).
Second: how is foreign policy altered? Would John Foster Dulles still engage in his policy of containment, forming NATO and SEATO?
Third: what would be fallout/collateral effects? Would there still be a Hollywood blacklist as there was in OTL?