Defending Earth before Space Battleship Yamato's war

How should the British, American, and French sections of the UNCF prepare for the coming Garmillas war with advance knowledge of the Yamato timeline?

Disperse the population and industrial base, build missile-heavy delaying forces and asteroid ambush sites, defend Earth from planet bombs, and establish a search network around Mars.

The scenario gives British, American and French UNCF commanders advance knowledge of the war in Space Battleship Yamato. An initial proposal to prevent Earth's first strike runs into disagreement over whether the Garmillas would impose their rule anyway. Dr. Clarke proposes concealed asteroid settlements, production lines and fleet facilities so that devastation on Earth cannot end the war effort. Fleet develops missile-heavy ships to delay the invasion and intercept planet bombs, with physical shells as secondary weapons. Ron concentrates on a sensor and rescue network around Mars, where outside assistance is expected to arrive. These plans combine dispersed industry with mobile forces and prepared asteroid ambushes, while captured enemy ships offer a route to understanding superior technology.