回複：讓我們分析一下如果打了911，會發生什麽。首先警察會趕到

I think your father's behavior was caused by boring or something disappointed in the U.S. That is very common for older people, but your father is in a bad temple.
What I suggest that if you move to in a chinese community,maybe give your father more chances to talk with people, then let him feel better.