Best to avoid the subject all together, it's a very sensitive issue for many Canadians.
The point is, by invading Iraq, the US gains control of the oil, and can produce it at cost, as opposed to having to buy it all through OPEC, at their rates, which are higher than what America would like to pay. The sort of profit there would be if they didn't have cover OPECs share would be enormous, and it would be a massive shot in the arm for the US economy. In truth, the US economy really needs that shot in the arm.
The war in Afghanistan was planned months before the Sept 11 attacks, because they wanted the oil they thought was there. It turns out there is a lot less oil there than they thought, which is why they have moved Iraq up on the "to be invaded" agenda.
http://www.rense.com/general15/afgha...warplanned.htm
http://www.wsws.org/articles/2001/no...afgh-n20.shtml
http://www.btinternet.com/~nlpwessex...sheikhgate.htm
You are right to think that a ground war in Iraq will be unpleasant, as far as wars go(there is no pleasant war). In the Gulf War, it was a matter of forcing Iraq out of Kuwait, and bloodying their nose.
In the coming war, the US will be overthrowing the government of Iraq, although "regime change" sounds so much nicer, doesn't it. This means they have to capture or kill all troops loyal to Saddam Hussein, and in case you don't know, many Iraqis are fanatically loyal to him. Not all of course, but a great many Iraqis see him as their saviour, the fearless leader who stands up to the greatest evil, America.
If you want to know why the US is hated by many people, it comes down not to how things are done in America, it comes down to what the US does outside their borders. In the last 50 years, Americas foreign policy can be summed in one word. Evil. That is how many educated people see it, even in America.