to persist at that level, they find themselves curbing public spending and fending off rising domestic discontent or even incipient revolt.

At the peak of their glory, the petro-states played an outsized role in world affairs. The members of OPEC, the Organization of the Petroleum Exporting Countries, earned an estimated $821 billion from oil exports in 2013 alone. Flush with cash, they were able to exert influence over other countries through a wide variety of aid and patronage operations. Venezuela, for example, sought to counter U.S. influence in Latin America via its Bolivarian Alliance for the Peoples of Our America (ALBA), a cooperative network of mostly leftist governments. Saudi Arabia spread its influence throughout the Islamic world in part by financing the efforts of its ultra-conservative Wahhabi clergy toestablish madrassas (religious academies) throughout the Islamic world. Russia, under Vladimir Putin, used its prodigious oil wealth to rebuild and refurbish its military, which had largely disintegrated following the collapse of the Soviet Union. Lesser members of the petro-state club like Angola, Azerbaijan, and Kazakhstan became accustomed to regular fawning visits from the presidents and prime ministers of major oil-importing countries.

That, of course, was then, and this is now. While these countries still matter, what worries these presidents and prime ministers now is the growing likelihood of civil violence or even state collapse. Take, for example, Venezuela, long an ardent foe of U.S. policy in Latin America, but today the potential site of a future bloody civil war between supporters and opponents of the current government. Similar kinds