The US did it in WWII because the Royal Navy and the US Navy were the two biggest most powerful navies in the world, specially in the Atlantic. If you think th

The US did it in WWII because the Royal Navy and the US Navy were the two biggest most powerful navies in the world, specially in the Atlantic. If you think the US would go so far as to block Europe from buying launches on US launchers, then the US could also easily blockade South America. Certainty, blockade is another level to just cutting business ties but its certainty not comparable to WW2.