The year is 2390. Humanity has taken to the stars and achieved interstellar travel. Humans now inhabit eleven planets in four different star systems. While most of these planets required sophisticated and expensive techniques to colonize (too frigid, barren, or hot to otherwise support human life naturally), two planets are beautiful terran-style worlds. One is Earth, and the other is (for the sake of this question) New Earth.
Sadly, diplomatic relations between these two planets have been souring for several decades and recently exploded into all-out war. Unfortunately for Earth, New Earth’s space fleets were much better prepared and have essentially annihilated Earth’s entire space-faring navy. At this point, Earth and its five billion inhabitants are now severely vulnerable, but can certainly continue to build threatening ships and anti-orbital defenses on the ground. As a result, they have not surrendered.
New Earth wants to ensure that Earth’s citizens are unable to pose a present or future threat to its new space empire while minimizing the cost to themselves. What is the best strategy to accomplish this?
The most obvious solution to this problem is to simply start pushing (or dropping) moderately sized asteroids into the atmosphere. This is certainly a quick way to guarantee victory, but violates the following bonus objectives that the New Earth navy is hoping to fulfill with their strategy:
- Earth-like planets are rare, so destroying the planet is not an option.
- For the same reason, mass-extinction events that make the planet unsuitable for human habitation is not an option.
- Massive loss of civilian life should be avoided if possible. It won’t look good on the news at home if millions of innocent people die.
- New Earth wants an unconditional surrender from Earth.
- Earth’s surrender should happen as quickly as possible to avoid public opinion souring at home.
This may be updated as more information is requested.
- Wormhole-based FTL travel exists (hand waived) that allows medium-large ships to travel long distances quickly, but is expensive.
- Earth is ruled by a single governing coalition.