Machines Can't buy oil. People buy oil. They also buy mobile phones for $650.00 without a contract. They also travel much more with better all-inclusive deals on zero emissions hydrogen fuelled jets to exquisite exotic and also pristine "old world" travel destinations. They are kept safe from pirates and hi-jackers by the world's "Services" formally known formerly as the military. The truth is that Jesus is the mighty counsellor and the prince of peace. No matter what, there will always be peace. There is no war in Heaven. God is always at peace. He will be at peace in the event of human annihilation. God's time is not our time. A day unto God is like a thousand years and these subway tunnels in your city will be a great archaeological excavation for some future humanoid or human race. Who knows what they might look like but with adaptation being a good feature of technological or genetic improvements over time, they will probably have webbed feet and will be able to breath under water. You have heard this before. Your genes are likely to be in them. The bible says that "Out of water, came life." If anyone is in a hurry to shake his fist at His maker or to see Him, they do not have to bring the whole entire town with them. As Jesus said to Judas, "..do what you are doing and do it quickly." God evicted Satan from Heaven. He will evict people or civilisations from earth who cannot agree with the fact that the earth is His footstool. There is no war in Heaven. Who knows what it takes to cause a massive lava overflow to succumb civilisation on every continent? I am sure someone has made calculations in the name of a PH.D in geology. Their father was the first designer of a blended wing jetliner running on zero emissions hydrogen fuel. If in doubt, God knows the answer. Read Matthew 24.