[ben_jones]

Ok the historian in me has to say something. The US is only a superpower because we pilfered an incredibly large and resource-rich land mass and had incredibly good geopolitical luck during World War One and Two. And that involved dropping a nuclear weapon on a civilian population. Those circumstances are NOT repeatable.

[MR4D]

The US is the only superpower because of two reasons:

1 - The Atlantic 2 - The Pacific

Those two present enormous competitive barriers in a fight.

[eternalban]

The British Empire changed its board of directors.