A true War on Terror is an ongoing battle that will go on continiously but it is also necessary to protect the freedoms that we cherish. If it stops then new terrorists will come along to replace the old ones and that can not happen. It is difficult but it must continue.
A War on Terror can truly be won. This is because it relies upon having enough weapons and also people on the side of the good guys. Usually people will change their minds to suit the tides of political correctness. If the War on Terror were to be a politically correct phenomenon, then it would gain substantial support and win the war.
Terrorist come in many forms. Some are members of actual terrorists groups and some are individuals. If you could locate all of the terrorist in the world in a day and exterminate them, you would still not end terrorism. Terrorism is an idea. You can't defeat ideas with force. The only way to slow terrorism is education. This does not end terrorism all together, but will go along way to teaching people better ways to solve there social issues.
I do not believe the War on Terror can ever truly be won. I believe this is another example of bad American thought. Much like the War on Drugs where it's impossible to remove all drugs from society, it is impossible to remove all terrorists from society as well. The War on Terror is too broad.
I think that the idea of a War on Terror is one that is based on fighting an enemy of the current time, not fighting the ideology that creates terror. There will always be terrorism. That's why I don't think such a war can ever be truly won. But it doesn't mean we should stop fighting.