The odd thing is, that besides Wacht am Rhein, there are a few other real or quasi-anthems celebrating the defeat of one particular foe in history. The Star-Spangled Banner takes a few swipes at the British, which is why the second and third verses are nearly never sung. The Maple Leaf Forever celebrates British/Canadian victories over the US at Queenston Heights and Lundy's Lane. And those are just two examples.
Frankly, I'd choose "God of Our Fathers" for the US anthem: there are no references to a particular denomination, and would appear to be equally acceptable to Christians and Jews. And it's got a great early-20th-century style, like "Land of Hope and Glory", that Theodore Roosevelt would have liked.