No earthly sovereignty on Mars unless instituted by those with the Manifest Destiny to colonize it. My guess the first things to go to Mars will be research equipment and gear to begin rudimentary camps. Then weapons. Then equipment to try to create conditions to grow food, find water, and research on ideas to improve atmospheric conditions for mammalian life to live outside closed camps. Then, attempts to launch from Mars to the Asteroid Belt to capture and bring asteroids into Mars or Earth Orbit to mine for resources, or, it might be cheaper to send automated mining equipment to dig into asteroids in the asteroid belt itself and simply shoot them back to Mars or to Earth to splash in the ocean where they can be retrieved by earthlings. Imagine just one of the old astronaut capsules filled with gold or other rare earth minerals.
I can imagine thousands of little jetpack robots that will drill themselves into an asteroid.
into asteroids in the asteroid belt itself and simply shoot them back to Mars or to Earth to splash in the ocean
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That said, Mars doesn’t need troops once it can move asteroids - they can just as easily send a water composition asteroid to splash in the ocean as a nickle-iron one to splash on any continent on any target.
We now know there is a lot of water ice on Mars, and getting into orbit from Mars due to its lower gravity and thin atmosphere would be much, much easier than from Earth, and it’s much closer to the asteroid belt. So with a ready source of power (fission? fusion?) it’s quite conceivable that Mars would become the primary space hub.