[Mo1]

One government official noted, however, the United States has no authority to require security measures of non-U.S. carriers whose flights originate outside the United States.

Ummmm .. we can deny air space for Canada to fly

[kitkat]

***Ummmm .. we can deny air space for Canada to fly***

We're on the same page, Mo. I wonder if we used this as an inducement to Canadian officials.

[GOPJ]

You're solution would get attention, the threat alone might work... .

Ummmm .. we can deny air space for Canada to fly

[Squawk 8888]

we can deny air space for Canada to fly

I don't think you want to go there- nearly all transatlantic flights from or to the USA use Canadian airspace, and the Gander Oceanic control centre manages about half of all transatlantic flights (half the north atlantic). A pissing match would harm Canada, harm the US economy even more, and would not prevent a single attack.