There's a mountain of evidence that the global system is now so large, fast, and fluid that nation-states have lost control. The market is now in charge, and even the most powerful nation-states are merely participants. Worse, uncontrolled markets are prone to disruptions (price spikes, shortages, starvation, etc.), corruption (hollow states, predatory money, etc.), and melt-downs (economic, environmental, etc.).
However, optimists, like my friend Tom Barnett say this is to be expected. The global system is merely a new frontier, a periphery, soon to be settled by a new form of global governance. I'm not nearly as sanguine.
In my view, the global system is an open source platform (in engineering speak, a bow-tie control structure). This type of platform grows very quickly due to simple rules of interconnection and is VERY resistant to upgrades after they are established. This simplicity is actually a design feature, not a flaw, since it enables a bewildering level of complexity to develop on the periphery (the two ends of the bow-tie, radiating outwards). Doesn't look like a frontier to me...