War against terrorism: nonsense or true?

I really believe that Twin Towers were intelligently demolished and the official version is government propaganda. If you think carefully, an airplane impact could only damage the building structure upwards, maybe some floors beneath, but never make the whole building accurately collapse as it did from top to the bottom. Of course, the majority of americans would eat what his government is giving them, without considering, so if the government says arabs, it's arabs. USA is the country on its own, quite far from the arabs as well as alternative opinions. Very few people would actually say "Hang on, the story looks well too prepared to be true". Anyway, americans are not the first victims of propaganda in this world. Did you actually wonder, how people could not only stand, but also praise  Stalin's or Hitler's tyranny during 30s and 40s, while millions of people were sentenced to death? State propaganda has always had very strong power and influence on the population. US government calculated things very well: if the majority catches the official opinion, those who oppose, won't go far, remain unconsidered or, even worse, prosecuted for supporting terrorism. Nothing new in this world, just open an average world history textbook. The official version is somehow very comfortable for the US government, opening all the doors around the globe and freeing their hands to do whatever they want for the sake of "fighting against terrorism". In the reality, "war against terrorism" is complete nonsense. Terrorism is abstract and is not bound to a region or a concrete country you can make war to. You destroy it here, it's going to appear there, you destroy it there, it's going to appear somewhere else. Moreover, destorying one country you make its population raise against you. I would not like to see tanks of some foreign country in my town, even if they come with a good mission. It could be more effective to look for eliminating the reasons of terrorism, if you really want to get rid of it.
Let me repeat, if you really want to get rid of it.
If US benefits from fighting against terrorism, it also might be interested to support terrorism in order to retain its benefits from fighting against it. I am not going to list all the benefits US government may have from this war - they are all well known. The only one thing I try to get to you is that to find someone resposible for something, whatever it is: war, terrorism - you only need to answer an old latin question : "Cui bono?".