1964 - JFK withdraws U.S. troops from South Vietnam, ensuring America will enjoy peace and prosperity.
1968 - JFK sends U.S. troops to Northern Ireland to liberate the oppressed Catholic minority, setting off the British-American war of 1968-1973.
I presume P.J. O'Rourke, who is a Prod, came up with that one.
How much did the existence of the Notre Dame Fighting Irish help deflect natural Irish-American competitiveness away from the Belfast conflict (1969-1997) and toward beating USC?