A crazy little strategic idea I am playing with. Perhaps some political novelist will run with it.
If Musk's Boring Company was to quietly offer Russia and Japan to do short car tunnels between Sakhalin Island and Hokkaido Island and at the same time between Sakhalin and Siberia at the nearest point near the Amur River, both countries could experience a low impact land contact without any sovereignty questions as the third party is doing it for money. The Boring Company's tunnels are too narrow for anything bigger then one Tesla car going one way. They are not a major danger.
Distances are 5 miles to Siberia and 20 to Hokkaido. The Boring Company link shows Tesla going 127 MPH under Las Vegas in their tunnels.
It might be enough of a confidence builder for the two nations to then consider building industrial-sized train, truck and pipeline tunnels afterwards. This would be in the American strategic interest, in Russia's interest and in Japan's.
Think about it being a minor stake in the heart of the ongoing Chinese absorption of Eastern Siberia, giving Japan options of alternative sources of resources that don't transit the South China Sea and new markets for both countries to operate in. They might even help Russia develop Siberia.
Siberia is currently well on its way to being a near-future Chinese colony. This might not stop that, but would begin to open up options for Russia and Japan.
It's much, much cheaper and shorter to build than the expensive idea in the video below that Japan keeps dredging up, and has a lot fewer shortcomings:
