Under what circumstances would the US need to invade Canada?

[paxamericana]

While relations are not the best with the play pretend non Americans , when would tension boil over into direct conflict?

One such scenario would be over Arctic maritime access and claims. Should Canada inhibit the st Lawrence Seaway or similar Arctic body of water it could generate strategic concern for American interests. As climate change make the northern hemisphere more economically accessible, there will be more opportunities for competition. 

[John Johnston]

13 minutes ago, paxamericana said:

While relations are not the best with the play pretend non Americans , when would tension boil over into direct conflict?

One such scenario would be over Arctic maritime access and claims. Should Canada inhibit the st Lawrence Seaway or similar Arctic body of water it could generate strategic concern for American interests. As climate change make the northern hemisphere more economically accessible, there will be more opportunities for competition. 

You idi@ts are too busy stealing gas and attacking Capitol Buildings and getting yourselves mired in endless wars. We are not worried. 😄🤣