3 trillion is about 20% of our GDP, but not the country's actual value. I don't think that number could be quantified. It is probably in the hundreds of trillions if you consider all land value, assets, everything. Last I had heard, the wars running total was about 1.3 trillion over the last 10 years. I'm not sure about the other things you wrote.
bin laden isn't the only terrorist we've been fighting so you can't attribute 3 trillion dollars to him alone.
I shot Bigfoot yesterday. I ate him and dumped the remains in the lake before I could prove it. Just take my word for it. Seriously.
True...but a figure I've seen thrown around is the 9/11 attacks cost al qaeda ~500k. Considering estimated cost of the War on Terror so far, I'd say if their intent was to cause huge expenditures, they had a pretty good ROI.
As well as the losses in the Dow, the airline industry, the added cost of security in every aspect of our lives, etc.