To me “bipartisan foreign policy” means a mutual effort, under our indispensable two-Party system, to unite our official voice at the water’s edge so that America speaks with maximum authority against those who would divide and conquer us and the free world. It does not involve the remotest surrender of free debate in determining our position. On the contrary, frank cooperation and free debate are indispensable to ultimate unity. In a word, it simply seeks national security ahead of partisan advantage. Every foreign policy must be totally debated (and I think the record proves it has been) and the “loyal opposition” is under special obligation to see that this occurs.

Arthur Vandenberg (1884-1951) American politician and statesman
The Private Papers of Senator Vandenberg, ed. Arthur H. Vandenberg, Jr. (1952)