To expand on the previous answer, yes, nobility obligates. A person of power and prestige is obligated to provide good examples of behavior or to exceed the minimal standards of decency. The definition states: benevolent, honorable behavior considered the responsibility of persons of high birth or estate.
Historically, noblesse oblige carried with it the concept of selfless acts of duty toward those who did not have the power, prestige or money that came with nobility or power. The idea of squandering the wealth of a nation by kings is the exact opposite of noblesse oblige. (I find the history of this expression interesting since the French Louis (plural) spent a good deal of their time spending money on the 100 Years War, entertaining and building palaces.)
By today's standards, examples of noblesse oblige include Bill Gates and the Gates Foundation, Jimmy Carter and Habitat for Humanity, Bill Clinton and the Kiva Project. And, my favorite, Spider Man: "With great power comes great responsibility."