[doikor]

> Could South Africa join NATO? Thailand?

South Africa or Thailand are not in the area covered by the treaty so no. Hell even an attack in Hawaii would be outside the treaty according the the US department of defense.

This is also why Australia and New Zealand are not part of NATO.

> Russia themselves asked to join but were rejected.

Except they were not. They were told to apply like any other nation and they did and were in the program but their constant threatening (and actual use) of force against their various neighbor countries slowed and eventually stopped the process with a final severing of official relationships due to the invasion of Crimea in 2014. Again the treaty is quite clear in this as a requirement to join nato.