My reason being, is that let's say we didn't. The Al Queada (don't care how it's spelled) take over Iraq, let's also say that the Iraqi government has nuclear weapons. What now? The Al Queada send nuclear missiles to Chicago, New York, Tampa, San Francisco, Las Vegas. And more large cities to decimate us. Well according to "political correctness" sending military troops would be insulting, or might lead to the loss of innocent lives. Well if we don't invade, the lives of tens of millions of Americans are at stake! Now, I'm not saying that our lives are more important than theirs, but that does make sense.
I don't think it will necessarily help the situation, but I think it is still a good idea if we have a military prescence in the country. I don't think we should send troops with the attempt to regain control, but basically to simply monitor the situation and have eyes and ears on the ground.
It is completely understandable why some are hesitant about sending in troops, especially since Operation Iraqi Freedom and the subsequent US occupation of Iraq was incredibly unsuccessful. However, it's important to recognize that Iraq is facing a real threat to democracy and freedom at the hands of the terrorist group ISIS. People have a duty to help one another, so it is important that the US intervenes.
Yes, the US should be sending military personnel to Iraq because they have been invited to do so by the Iraqi government and have the military capablity needed. The Iraqi government needs international support to suppress the rebels who are trying to destabilise the country. The US should do what they can to bring stability to the Middle East.
In order to assist Iraq in peaceful communication and negotiation there should be US Military presence. It is not to do with being at war with anyone, more to ensure that there is some assistance offered in order to attempt to have peaceful communications. Americas presence should be one of reassurance and assistance in this time of need.