Planetary defense is simpler than a planetary attack as a fleet of weapons approaching a planet will be visible in advance. As a result, there is no first strike advantage in interplanetary war.
At least, assuming current technologies with nuclear missiles. Maybe near-light-speed kinetic weapons will be unstoppable as well as directed explosions of multigigatone nukes.
Nanotech also favors defenders as the whole surface will be covered with nanobots and secret replication is impossible.
You don’t need a fleet of spaceships. One spaceship could throw thousands of nukes from distance (like meteorites) so that they all reach different parts of the planet at the same time. Add thousands of decoys; the defenders will not be able to shoot down all of that.
If the attack is against Earth, you could instead throw thousands of capsules containing highly contagious deadly airborne virus, releasing the virus in the atmosphere.
Or both. Throw the virus first, the nukes two days later. People will bring the deadly virus to nuclear shelters.
I still think that space attack is taking longer time—than missile attack during a nuclear war on Earth, and thus anti-ballistic missile systems of the future will be even more effective in its stopping; including space lasers. Incoming spaceship will be visible for days or even months.
Therefore, the only winning strategy is to make the attack spaceship either invisible or moving with very high speed. It is contradictory requirements as getting the spaceship to the high speed requires a lot of energy (or time if gravitational maneuvers are used).
Planetary defense is simpler than a planetary attack as a fleet of weapons approaching a planet will be visible in advance. As a result, there is no first strike advantage in interplanetary war.
At least, assuming current technologies with nuclear missiles. Maybe near-light-speed kinetic weapons will be unstoppable as well as directed explosions of multigigatone nukes.
Nanotech also favors defenders as the whole surface will be covered with nanobots and secret replication is impossible.
You don’t need a fleet of spaceships. One spaceship could throw thousands of nukes from distance (like meteorites) so that they all reach different parts of the planet at the same time. Add thousands of decoys; the defenders will not be able to shoot down all of that.
If the attack is against Earth, you could instead throw thousands of capsules containing highly contagious deadly airborne virus, releasing the virus in the atmosphere.
Or both. Throw the virus first, the nukes two days later. People will bring the deadly virus to nuclear shelters.
I still think that space attack is taking longer time—than missile attack during a nuclear war on Earth, and thus anti-ballistic missile systems of the future will be even more effective in its stopping; including space lasers. Incoming spaceship will be visible for days or even months.
Therefore, the only winning strategy is to make the attack spaceship either invisible or moving with very high speed. It is contradictory requirements as getting the spaceship to the high speed requires a lot of energy (or time if gravitational maneuvers are used).