What is "The Eagle" about?
On one level, the poem could just be about the experience of an eagle. He's up on a mountaintop, by himself, in a clear blue and sunny sky. The eagle is up so high that the sea looks like wrinkled cloth or paper below him, and he watches over everything before diving down and striking his prey.
On another level, the poem could be interpreted as a symbolic comment on absolute power. In this case, the eagle represents a supreme ruler with unlimited power. This ruler holds onto "the crag," his authority, with "crooked" hands that could refer either to bent talons or corrupt practices. He is alone, in his absolute power because to share that power would mean his is no longer absolute. Everyone else is below him; "crawl[ing]" is an action associated with the powerless. He keeps an eye on everything from the seat of his power, perhaps his castle atop a mountain, and when he loses his position or "falls" from power, it is violent and swift, or, perhaps, strikes out swiftly and violently when someone threatens his power or disobeys him.