Mass Effect & Mass Effect 2
Because of their long lifespan, asari tend to have a 'long view' not common in other races. When they encounter a new species or situation, the asari are more comfortable with an extended period of passive observation and study than immediate action. They are unfazed that some of their investments or decisions may not pay off for decades or centuries. Matriarchs can seem to make incomprehensible decisions, but their insight is evident when their carefully-laid plans come to fruition. In interstellar relations, this long view manifests in an unspoken policy of centrism. The asari instinctively seek to maintain stable balance of economic, political, and military power.
Traditionally, asari spread their influence through cultural domination and intellectual superiority. They invite new species of advanced development to join the galactic community, knowing that their ideals and beliefs will inevitably influence the existing culture.