苏联解体后，与美国对抗的超级大国不存在了，爆发世界大战的危险减少了许多，但是局部战争的危险并没有减少。这种危险主要来自国家内部，还是来自国家之间？有没有可能导致第三次世界大战？虚拟社区能取代国家成为人们的生活单位吗？

We are in an unprecedented period because for the first time ever1 there is2 only one superpower. In a sense there is therefore no balance of power3. Will this situation persist? Well, the answer to that depends on whether you're an optimist or apessimist. Optimists believe that power politics4 will be subsumed within a constitutional5 world order shaped by6 a global ideology7 of human rights.

I'm skeptical about this myself, more persuaded by8 the pessimists who believe there is no escape9 from power politics. They see another superpower emerging eventually, either through10 the decay of the United States or as the result of an outright challenge. The most obvious candidates would be China or a revitalized11 Russia.

Others reject this dichotomy12 completely and anticipate a more evolutionary path13, sometimes called "the new medievalism", in which the relentless14 advance of information technology results in the demise of the state as we know it15. The idea is16 that global communications will simultaneously empower individuals to create transnational virtual communities17 and make it more difficult for governments to control their populations18. The result will be a new political landscape19 with overlapping jurisdictions20 for21 different aspects of life in place of territorial states with distinct jurisdictions.

Again, I'm skeptical myself. We can't ultimately exist as virtual communities; we all have to live somewhere and pay our taxes. The resurgence22 of nationalism argues against23 this model in any case. In the first half of the twentieth century many believed that nationalism would give way to24 a world organized on liberal or communist principles; some even believed in world government. But today the pressure25 is in the opposite direction, towards ethnic separatism26.

Since the end of the cold war, much of the attention focused on nuclear27 and strategic issues has drained away28 — to a dangerous extent in fact. Weapons of mass destruction have not disappeared and non-proliferation29 has now been seriously undermined30 by the nuclear tests in India and Pakistan.

For the foreseeable future, though, a third world war seems unlikely; there is no major ideological fracture31 severe enough to sustain it32. War itself won't disappear, but it will continue to be regional or local, more often within the state than between states.

What about the balance of power? Well, the one thing that we can be sure about is the experts will get it wrong33?nbsp;how many of us predicted the end of the cold war and the Soviet break-up? Our job is not to predict the future but to improve understanding34 of the world we live in. On that front35 at least, I'm optimistic about progress.