Two years on, the Arab spring, or what's left of its verdant virtues, has brought about far more than the end of the authoritarians and the extractive regimes they led.

The myth of the strong and cohesive Arab state has been laid to rest too. From North Africa to the Levant—and, over time, perhaps in the Gulf as well—a process of state decentralization, perhaps even fragmentation, is under way that will carry hugely negative consequences for the region and American interests. And there may be very little the United States can do about it.

For the past fifty years, America dealt with an Arab world composed of two kinds of authoritarian leaders: First, there were the adversarials—the PLO's Yasser Arafat, Iraq's Saddam Hussein, Syria's Hafez and Bashar al-Assad, Libya's Muammar el-Qaddafi. Then there were the acquiescents—Egypt's Hosni Mubarak, Tunisia's Zine Ben Ali, Yemen's Ali Abdullah Saleh, and the kings of Morocco, Saudi Arabia and Jordan.

For the most part the United States opposed the first group and cooperated with the second. Together, these leaders represented a regional order that, while volatile at times, offered a general stability in a critically important part of the world. These strongmen and their regimes provided support for a variety of America's policies in exchange for economic and military assistance and a pass on human rights. America became quite comfortable with its friends and even sometimes with its adversaries, including Arafat, the Assads, Saddam and Qaddafi.

Now all of that has changed. The Arab acquiescents are gone, and with the exception of Bashar al-Assad (still above ground but much reduced in stature and power) the adversarials have gone the way of the dodo too. The authoritarian kings in Jordan, Morocco and Saudi Arabia remain, offering up a paradoxical continuity with the old order. But if they cannot find a way to get on the right side of the reform issue, the bell may toll for them as well.

What is stunning about this transformation is that the structures built by the authoritarians collapsed so quickly. In some cases, such as Egypt, the institutions of the authoritarian state remain (security services and the military), but they have become independent interest groups at the expense of national control over economic resources and good governance. Indeed, with the exception of Tunisia, which seems to have the best chance of making this transition, the faux republics seem in various states of crisis, unable to govern effectively and competently.

Syria is imploding. Libya lacks coherent government at the national level and is susceptible to tribal and geographic tensions and the challenge of too many guns and grievances. Egypt, the largest and most important Arab state, seems mired in an endless dysfunction in which the democratic enterprise is in the hands of the nation's two least democratic forces—the Islamists and the military—while a secular/liberal opposition remains leaderless and divided, with no real strategy of how to compete successfully.

These recent trends are reinforced in other parts of the Arab world by a process of dysfunction and decentralization that was under way long before the Arab spring. Lebanon has been a non-state for years. It possesses the trappings of statehood, but its central government can’t control the forces of violence within Lebanese society, lacks the confidence of all its sectarian groups, and has failed to maintain sovereignty over its own territory. The hollowing out of Lebanon is likely to continue even if Hezbollah's influence is reduced with the travails of its Syrian backer.

Iraq continues to struggle with a lack of political cohesion and an abundance of violence. It likely it will continue to devolve into a more centralized Kurdish entity, an aggrieved Sunni minority and a dominant Shia community. Palestine remains divided among Hamas, which controls Gaza; the Palestinian Authority, which holds sway over parts of the West Bank; and Israel, which retains the larger piece of that territory. Today’s fragmented Palestinians resemble a Noah's Ark with two of everything—constitutions, security services, even visions of where and what Palestine is. It can’t be considered a cohesive national movement.

Several months ago I wrote that I didn’t think the Arab state system would likely implode in the face of these new challenges. Too many in the region and outside have an investment in maintaining the fiction. And the arc of change is a long one. We shouldn't impose the bias and prejudice of low expectations. Perhaps in time democratic life and better governance will indeed prevail.

But for now the trend lines don’t look promising at all, and you have to wonder what, if anything, will alter them. The three elements required for democratic life in any form simply aren't evident in the Arab world: leaders who rise above sectarian, religious and ethnic affiliations and govern in the best interests of the nation as a whole; institutions that are deemed authoritative, legitimate and inclusive and not mere playthings in the elites’ struggle for power; and an accommodative process that contains and manages even the bitterest of debates without spilling over into violence or political pressures that paralyze national life.

The absence of these attributes spells trouble for America in a region where the space available for its interests is likely to shrink.

Good riddance to the authoritarians. But America will no longer get the pass that it did from some of them on its most unpopular policies, such as support for Israel and opposition to Hamas. Rising Islamist currents will further constrain these regimes’ cooperation with the United States. And decentralized states unable to control weapons flows and territory could become easy targets for Sunni and Shia insurgents.

The United States will continue to manage through these tests and challenges. It won't be pretty. But America will remain oddly afloat in this messy, broken world through a number of factors—its geographic distance from the region, its growing independence from Arab hydrocarbons, its relative success in protecting the homeland from terror, the very dysfunction of some the Arab states themselves and their ultimate need for U.S. support and largesse.

But the reality is that we are stuck in a region we can neither abandon nor fix. Worse, we're trapped there as one regional order with which we had grown quite comfortable gives way to another with a very uncertain future. America could never save the Arabs. That isn’t new. What is new is that the dysfunction now gripping the Arab world may well mean that the Arabs will have a much more difficult time saving themselves.

Aaron David Miller is Vice President for New Initiatives and Distinguished Scholar at the Woodrow Wilson Center. He served as an adviser to Republican and Democratic secretaries of state on Arab-Israeli negotiations.