Like the concrete masonry, the 1945 division of Germany and of Europe was removed from the map. The way opened to the end of the cold war, the advance of democracy and free markets into eastern Europe, and the enlargement of the European Union.
Two decades later, it is clear that the world won huge political and economic benefits from the collapse of communism. Despite today's difficulties with global terrorism, the Middle East and economic crisis, the end of superpower rivalry has made the world safer, freer and richer.
Difficulties remain with completing the economic integration of Germany and of eastern Europe, where living standards remain below western levels. The economic crisis will delay efforts to close the gap. But with hard work it can be done.
East European states have worked wonders in establishing democracy where it had barely existed. But they must do more to deal with the baleful legacy of communism, build trust in public institutions and fight corruption.
Meanwhile, there are signs the division between Moscow and the west that once ran through Germany, is re-emerging further east, in Russia's borderlands. Besides the successes of 1989 and its aftermath sits a failure by the west to engage Russia properly, reform Nato and develop new security structures. Perhaps, given Moscow's deep-seated love of empire, the effort would have been futile. But it should have been attempted. Now, Europe may be blighted by a dangerous new grey zone between the EU/Nato border and Russia.
But these challenges must be put in perspective. The end of the Soviet empire – and later of the Soviet Union – was not followed by nuclear disaster. The Red Army retreated painlessly from central Europe. The ex-communist states did not, with the big exceptions of Yugoslavia and Georgia, collapse into civil war. For this Mikhail Gorbachev, Helmut Kohl, George H.W. Bush and others deserve credit. So do the brave east European campaigners and reformers who, wittingly or unwittingly, drove the revolution forward, Poland's Solidarity movement, Hungary's reform communists, the Czechoslovak dissidents and the young people who destroyed the Berlin Wall. All merit their place in history.
和那座混凝土的砖石建筑一样，德国及欧洲始于1945年的分裂状态也从此消失，由此打开了通向冷战结束、民主和自由市场进入东欧、以及欧盟(EU)壮大的道路。
二十年过去了，很明显，世界从共产主义的倒台中获得了巨大的政治与经济利益。尽管今天还存在全球恐怖主义、中东问题和经济危机这样的难题，但超级大国对立局面的结束，让世界变得更加安全、更加自由、也更加富裕。
德国与东欧经济一体化的完成依然存在困难，上述地区的生活水平仍然低于西方。经济危机将延缓消除差距的行动，但只要努力就可以实现。
从无到有，东欧各国在确立民主制度方面创造了奇迹。但它们必须付出更多努力来应对共产主义的贻害，构建对公共机构的信任，并打击腐败。
与此同时，有迹象表明，过去那条穿越德国、将莫斯科与西欧分割开来的界线正在更东的地方——俄罗斯的边境地区——重新显现。1989年及其后所取得成功的背后，是西方未能适当地调动俄罗斯、未能改革北约(Nato)、未能建立新的安全架构。考虑到莫斯科对帝国根深蒂固的热爱，或许这些努力都会是徒劳一场。但至少应该有所尝试。现在，欧洲可能会受到欧盟/北约边境与俄罗斯之间危险的新灰色地带的困扰。
不过我们必须客观看待这些挑战。苏维埃帝国(Soviet empire)——以及之后的苏联(Soviet Union)——的覆灭并没有引发核灾难。苏联红军(Red Army)毫无痛苦地从中欧撤离。除了南斯拉夫和格鲁吉亚这两大例外，前共产主义国家并没有陷入内战。为此，应该给米哈伊尔•戈尔巴乔夫(Mikhail Gorbachev)、赫尔穆特•科尔(Helmut Kohl)以及老布什(George H.W. Bush)等人记上一功。同样值得称赞的还有东欧勇敢的活动家和改革家（无论是否有意为之，他们都推动了革命的前进）、波兰的团结工会运动、匈牙利的共产主义改革派、捷克斯洛伐克的持不同政见者以及拆毁柏林墙的年轻人们。他们都应该在历史上占据一席之地。
