The power and influence of the United States has declined rapidly since the war in Iraq because American power, as it has been exercised in the world historically, has been exposed more to the rest of the world in this situation and in other situations.
So the US influence is declining, its power is declining.
However strong a military machine it is, power does not ultimately depend on a military machine. So power is declining.
Ultimately power rests on the moral legitimacy of a system and the United States has been losing moral legitimacy.
My hope is that the American people will rouse themselves and change this situation, for the benefit of themselves and for the benefit of the rest of the world.