Most of the “investments” in “stability” of the region have payoffs in the many decades.

By the estimate, peak oil is still a long time off, and just crossing peak oil does not mean that oil will become unimportant over night.

True, but much of the political importance of oil has to do with the threat of a sudden oil shortage. The first defense (for the US) is to create massive reserve tanks, the second is to befriend oil producing regimes, the third is to invest trillions propping up those regimes.