What happened after the us invasion of iraq in 2003

The 2003 invasion of Iraq lasted from 20 March to 1 May 2003 and signaled the start of the Iraq War, which was dubbed Operation Iraqi Freedom by the United States prior to 19 March, the mission in Iraq was called Operation Enduring Freedom, a carryover from the War in Afghanistan.

 We (the USA) never attacked nor set foot on North Vietnamese soil. Had we done that, it would have been over in a heartbeat. But our great leader, President Lyndon Bains Johnson, was afraid of initiating nuclear war with the Russians, and he would never allow a US invasion of the North. 
P.S. A couple of decades earlier, we invaded North Korea during the Korean war, turning a near certain Communist victory into the stalemate that the Korean war remains in today.