[Cultural Jihad]

I thought so, too. The capitalized term 'Union Jack' is more commonly associated with the flag of Great Britain, but there's a 1st level meaning here:

Main Entry: union jack
Function: noun
Date: 1674
1 : a jack consisting of the union of a national ensign
2 capitalized U&J : the state flag of the United Kingdom consisting of the union of the British national ensign

[Pyro7480]

Here's the U.S. Navy union jack. It's just an enlarged version of the star field from the American flag.