Will Iraq cause major changes to the United States?

We appear to be in this open-ended war in Iraq and depending on who is elected President, we could have troops there for years, if not decades.  Since we also have troops in Afghanistan, I'm reminded of what happened to the Soviet Union after spending a large amount of money in Afghanistan.  Does the United States face something similar by remaining in Iraq with borrowing money from other nations (i.e., China) and by not having a set goal that equates victory?