Scenario I:  Barely Keeping Afloat 
In this scenario, seen as the most likely one over the next several years, no one crisis will be so overwhelming as to threaten the international system even though collective management advances slowly.  Crises are dealt with ad hoc and temporary frameworks or institutions are devised to avert the most threatening aspects of them.  Formal institutions remain largely unreformed and Western states probably must shoulder a disproportionate share of "global governance" as developing countries prevent disruptions at home.  This future is not sustainable over the longer term as it depends on no crisis being so unmanageable as to overwhelm the international system.

This scenario, which I like to call "muddling through," is no doubt the most likely.   It is, after all, essentially the course we’ve been on since shortly after World War II.

The failures of the League of Nations that allowed that conflict to happen sparked the development of a more realistic set of institutions.   The United Nations was much more flexible than its predecessor, in that its creators allowed for the very real possibility that the Soviets and other major players would not see eye-to-eye with the West.   The Security Council provided a powerful collective security regime in the event of a shared vision on the part of its Permanent Members but, through the veto power, allowed a default to collective defense and state security in the event that any one of them objected.

Similarly, the economic regimes created at Bretton Woods proved very flexible and severable, with such institutions as the IMF and World Bank now performing very different functions than envisioned in 1944 and surviving the collapse of the fixed exchange rate mechanism in the early 1970s.

Scenario II: Fragmentation
Powerful states and regions try to wall themselves off from outside threats. Asia builds a regional order that is economically self-sufficient. Global communications ensure globalization does not die, but it slows significantly. Europe turns its focus inward as it wrestles with growing discontent with declining living standards. With a growing work force, the US might be in a better position but may still be fiscally constrained if its budgetary shortfalls and long-term debt problems remain unresolved.

This scenario is not mutually exclusive from the first.  Indeed, occasional retreats inward happen periodically even as the momentum toward globalization proves inexorable.

One could argue that the movement toward centralization of power in the EU puts a wall around Europe even while it tears them down internally.  Not only does the common currency, lack of internal barriers, and central regulatory measures provide rather strong incentives to do business intra-Europe but they pose rather substantial barriers to entry.   At the same time, moves to strengthen the EU’s defensive capability, while potentially providing economies of scale and removing redundancy and frustrations, also potentially undermines the need for transatlantic cooperation.

An intra-Asia trade regime that displaces the need for trade with the West strikes me as decidedly less likely.  It’s almost unfathomable that the Western consumer market can be replaced locally. But moves to break down barriers to commerce within Asia — and, indeed, Africa and Latin America — should be welcome, as they’d not only increase short term prosperity for the people who live there but also move us further down the postwar trend toward freer trade.

Ultimately, however, fragmentation is a short-term option that’s unsustainable in the longer run.  A more prosperous Asia is one that will want the benefits of increased trade with the West — and one finally able to do so on a more equitable basis.

Scenario III: Concert of Europe Redux 
Under this scenario, severe threats to the international system—possibly a looming environmental disaster or a conflict that risks spreading—prompt greater cooperation on solving global problems. Significant reform of the international system becomes possible. Although less likely than the first two scenarios in the immediate future, such a scenario might prove the best outcome over the longer term, building a resilient international system that would step up the level of overall cooperation on an array of problems. The US increasingly shares power while China and India increase their burden sharing and the EU takes on a bigger global role. A stable concert could also occur incrementally over a long period in which economic gaps shrink and per capita income converges.

This is the report authors’ preferred outcome, although the one that seems most fantastical in the current international climate.  (See yesterday’s "Global Governance: Vital But Impossible?")  Beyond that, yearning for a repeat of the Concert of Europe seems rather odd, in that the original was a rather spectacular failure, unable to stop a whole series of major wars among its players.

That said, while a formal institution along the lines of the Concert is unlikely, we’re already moving in this general direction through the aforementioned policy of "muddling through."   The EU is becoming a stronger global player simply by virtue of its cohesion.  And, while the U.S. isn’t "sharing" power with  China and India, we’re ceding it as a matter of practical necessity.  The shift from the G7/G8 to the G20 as the prime economic forum is the most obvious example. 

Scenario IV: Gaming Reality: Conflict Trumps Cooperation
This scenario is among the least likely, but the possibility cannot be dismissed. The international system becomes threatening owing to domestic disruptions, particularly in emerging powers such as China. Nationalistic pressures build as middle-class aspirations for the "good life" are stymied. Tensions build between the United States and China, but also among some of the BRICs as competition grows for secure resources and clients. A nuclear arms race in the Middle East could deal an equally destabilizing blow to prospects for continued global growth. Suspicions and tensions make reforming global institutions impossible; budding regional efforts, particularly in Asia, also are undermined.

The report authors are right:  the possibility is remote but not non-existent.  

The Chinese government is going to have a difficult time keeping up the massive growth needed to simply keep even with the needs of a growing and aging population.  And they’re going to have to figure out a way to make domestic consumption a much bigger part of the pie, given both internal demands and the practical limits of export-driven growth.  And the prospect of an Iranian bomb — which seems a virtual inevitability — could certainly lead to a regional arms race.

Then again, the prospects of these things could be forcing agents for greater cooperation. To the extent a nuclear Iran can be averted, it’ll come from a united front from the West, China, and India.   And the long-term success of China’s economy will require internal liberalization and coming into greater harmony with global norms.

James Joyner is managing editor of the Atlantic Council.