My point is, they CAN'T draft "natural born citizens." They have no claim on them. If the Canadians have a claim on them, they aren't natural citizens.
A man that can be compelled by foreign law to fight against his country is not a citizen who is free from foreign influence.
Listen, at first blush it seems like a rather ambitious move for a country like Canada to attempt to draft the president of the United States. But, I have to confess that I have never given much thought to that possibility.
HOWEVER, someone recently turned me on to this treatise on The Law of Nations. It's by a Swiss guy named Vattel who wrote it in French. I'm wondering what Vattel might say about the propriety of one nation attempting to draft into its army the chief of state/head of government of another nation.
See what you can find on that. I will abide by any rule Vattel endorses! ;-)