It's ridiculous to consider Canada or Mexico (or if we extend this farther, the EU and Japan) "vassal states". All of these countries participate in the US Capitalist regime willingly because they get rich too.

By your standard, do any of the considered "major alternative powers" (China or Russia) have allies?

Canada and Mexico aren't vassal states.

Why didn't they then sanction USA when they invaded Iraq or Afganistan? Should not such blatant breaking of international law result in breaking all economic ties until the responsible the politicians, their funders and soldiers involved are punished?

Even Russia and China didn't sanction the US. Does that make them vassals too?

Your comment isn't attached to the history of the situation.

Very accurate. The CIA is actively involved in the interference of their 'allies' governments.

Japan didn't break from US in this news article, it received permission to do so, likely so that it can remain in a defensible position against China.