> Why they do this?

Because it damages USA. As other thousands of nonsensical choices in the last years, America always, consistently, ends scammed milked, and holding the shorter straw. Everything in this government is designed specifically to the inch to humiliate and destroy US. Acting exactly like foreign enemy agents for fun and profit.

Or maybe because it could be used (in theory) to register submarine's position.

Or maybe somebody expects to benefit from the climate change in some way, and couldn't care less if half of the planet became inhabitable in the process. There aren't many other reasonable explanations.