It was as though we were half a step behind them each time we met. When the Centauri colony reported contact with craft of unknown origin, the people living in the various settlements in the Sol system were amazed, excited, filled with joy. We were no longer alone! It was real, and undeniable.
Two weeks later, when the next transmission from Centauri brought news of the opening of hostilities, that feeling of euphoria changed to one of dread. Mankind had stopped warring with itself centuries ago. With the exception of certain outlaw elements, the average person had no concept of war, or how to fight one. Yes, there were old warships drydocked in a station orbiting at the trans-lunar LaGrange point, near the James Webb historical site, but it had been decades since the reserve units charged with their maintenance had even powered them up.
All at once, though, those relics of man's warlike past became the Sol system's only hope of defense, and every available resource was put to making the small armada ready for action. But as further transmissions arrived from Centauri, we all began to realize that thirty ships, crewed by people with no experience in battle, would be of little use against the invaders if they came to Sol next.
And so Congress voted to build planetary defense grids on Earth, Mars, Luna, Europa, and Titan. The theory was that if we built large automated weapons arrays, the planets would be impregnable against any vessels that managed to make it past our small battle fleet.
The problem was time.
Centauri was about four light years away. At our best cruising speeds, it was a trip of about ten earth years, and that was damn little time to build the kinds of systems the plans called for. But the continuing transmissions from Centauri provided all the motivation we needed. Pictures of the aliens' relentless advance, and our kinsmen's inevitable defeat, spurred every industry to put aside everything except war preparations. When, two years after the first one, the final transmission from Centauri came through, a static-laced image of a man with hopeless, yet undefeated eyes bidding fair well to the rest of us, we figured we had at a minimum another five or six years to prepare. The aliens would want to take time to lick their wounds, consolidate their holdings, before they moved on, wouldn't they?