There's a couple of things going on here, some with counter-vailing impacts on the others.

First, structurally, the United States is committed to maintaining its hegemony in the short-term. This is represented in its fiscal priorities: defense expenditures represent approximately half of all discretionary spending; this number increases with the addition of the expenditures for the VA and Homeland Security (and other security or intelligence functions). Investments in infrastructure, innovation, education, and health are relatively minor. The largest social spending programs (Social Security and Medicare) are dedicated to improving the living conditions of the elderly. Of the already meager international aid budget, 25% goes to the top four recipients: Israel, Egypt, Afghanistan, and Iraq. The U.S. also leads in global arms sales, making this a primary source of revenue as well as a linkage to other governments. This means that institutionally the United States is geared towards maintaining its position in a specific strategic environment: one that requires the exercise of military force and wide-ranging security programs to sustain superpower status. The decline in U.S. military purchasing power also means that a greater amount of fiscal resources will be required to sustain a diminishing return on security effects. Without change, this means that the U.S. will eventually retreat from previous strategic priorities since it will not be able to sustain its security committments and will suffer from the consequent loss in credibility.

Second, absolute power is not as important as relative power. U.S. absolute power remains two to three fold ahead of the next competitor in military capabilities (Russia). However, there is a perception that (1) U.S. military capabilities are slowing in development relative to competitors and (2) U.S. military capabilities are either insufficient or inappropriate in their application. This explains the crisis in foreign policy debates about U.S. decline. But it also is empowering to elites in Moscow and Beijing; reference dependency is important. Moscow has two: the Soviet era and the Yeltsin administration, so current conditions (Russia has lost 1 war in 10 since 1991) give Russia confidence. The steady growth of China's capabilities is not revolutionary but methodical; but in the context of changings in U.S. relative power, that suddenly becomes a threat. This is similar to the situation prior to World War I when German and Austrian elites felt severely insecure about the long-term threat of Russia, even though Russia was decades behind in military development. It was the rapid growth of military and economic capabilities relative to Germany and Austria that produced the fear, not the absolute power.

Third, Russia is clearly dissatisfied with its position in the international community, while China's view is less clear (in my opinion). Russia will continue to openly challenge the U.S. while it appears that Russia's power is on the ascent relative to American power. In this situation, the declining power has no good options: as its strength declines, time works against it in restoring the status quo (and note, the status quo is always referenced as the apex of power, not the actual current conditions). Because potential losses are always more weighted than potential gains in measuring risk taking in policy decisions, there is an inherent incentive to preserve the remaining capabilities and not risk a hegemonic war, even though continued trends means that the prospect of a favorable outcome actually declines over time.

So, the U.S. is stuck in this paradigm that defines the parameters of its strategy options, even as its options become increasingly irrelevant and/or ineffective over time because the paradigm itself is changing. The U.S. needs to recapitalize on the generators of power itself (i.e. development, innovation, health), not the materialization of that power (i.e. military capabilities).