US-EU Single Market or merger scenario (Medium Term, at best):
In a world of 7 bn with China 1.3 & India 1.2, the US has not enough size (eg internal
market) to compete or have autarky. Even with Canada.
The EU has less of a size problem (0.5 bn) but its Internal Market not working well (one of the barriers: 20+ languages) and still it is not large enough!
But an US+EU of 0.8 bn (possibly plus Canada) have enough size-population,
resources & compatibility (in prices, costs, various standards, in spite their differences) to be 1 of the 3-4 major entities in world stage later in this century.