It's all very well to refer to flying eagles and tigers and whatnot, but am I the only one to gave a second thought to the word aliyah?

It originally means 'ascent' and has acquired the meaning of (r)emigration to Israel with the intent to live there permanently and definitively. This is how I understand the guy's argument: I will settle in Israel, become an Israeli and absolve my three years of compulsory military service there.

It doesn't seem to me that he will retain his British nationality. He will become an Israeli and the question about his loyalty is a non-issue.