I did some research.
http://www.barrypopik.com/index.php/new_york_city/entry/politics_stops_at_the_waters_edge/[quote
]"Politics stops at the water’s edge” is an old political adage, credited to several politicians. The phrase means that, in regards to foreign affairs, the United States is united and bipartisan. Alf Landon (1887-1987), unsuccessful Republican candidate for president in 1936 against Franklin D. Roosevelt, used the phrase often in 1936 and 1937. Michigan Republican Senator Arthur Vandenberg used the phrase in the 1940s and 1950s.[/quote]
So, yeah, it's appropriate here.
