We first see that the speaker sees unity as the emptiness that accompanies the status quo of the time. The Irish achieve a sense of false unity and order by accepting their condition. Here is where the paradox lies. The falcon cannot hear the falconer. In other words, mankind is lost and has no guidance or driving purpose anymore.
Mere anarchy is loosed upon the world.
Chaos is now what is feeding the situation, rather than its initial purpose. If the support of a rebellion gets out of hand, then the heart of that movement will dissolve. Therefore, disorder can give birth to both unity and anarchy and the fine line between the two is difficult to define.