What four countries are closest to the US?

This is an Excellent question. We know Mexico and Canada are two of the four as they are immediately adjacent. After this it gets a bit tricky. After looking at Guatemala from Texas against the Caribbean nations from the Gulf states, as well as Alaska at Russia, one sees that Russia and Cuba are the two next closest. At its closest point (the Diomede Islands in the Bering Strait), Russia is only 2.5 miles (4 kilometers) away from the US.

So the answer is Canada, Mexico, Russia and Cuba. After these would come the Bahamas.

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Actually, the Island of Bimini (part of the Bahamas) is closer to Florida than Cuba is, so the Bahamas should be ranked 4th.