This sounds like an ancient being who has seen continents rise and fall, seen entire species evolve and die, whose concept of history can be measured in geologic scales. The lifespan and the presence of mere mortals is of little concern. It is concerned about the longest of trends, of setting a small pebble in motion to cause an avalanche a decade from now.

In other words... the dragon can ask for whatever the heck you want, no matter how absurd. It's planning on the butterfly effect to produce what it truly wants 10 years from present day. Let the players try to connect almost nonexistent dots.