What is the main conflict in A Deepness in the Sky by Vernor Vinge?

Two races of people, the Emergents and the Qeng Ho, arrive at the OnOff star at the same time. The star is an anomaly in which the energy is literally switched off for two hundred fifteen of every two hundred fifty years. The two races have very different goals. The Emergents plan to mine and exploit the area for everything they can find of value while the Qeng Ho hope to establish a profitable trading relationship. The goals being at such odds, the two races clash and the Emergents mount a surprise attack in which the Qeng Ho are all but annihilated. The surviving Qeng Ho are forced into something akin to slavery with no real freedom to make their own decisions. The Emergents, however, are also crippled during the fight and realize that they are going to have to wait years for the Spiders to develop the technology necessary to allow them to travel back to their home.