We were right to invade Iraq in 2003 to remove Saddam Hussein, and to complete the job we should have finished in 1991.
Even with the absence of caches of weapons of mass destruction, and the mistakes we made in failing to send enough troops at first and to provide security from the beginning for the Iraqi people, we were right to persevere through several difficult years. We were able to bring the war to a reasonably successful conclusion in 2008.
When President Obama took office, Iraq was calm, al-Qaeda was weakened and ISIS did not exist. Iran, meanwhile, was under pressure from abroad (due to sanctions) and at home (due to popular discontent, manifested by the Green uprising in the summer of 2009).
The Obama administration threw it all away. It failed to support the dissidents in Iran in 2009, mishandled the Iraqi elections in 2010, removed all U.S. troops from Iraq at the end of 2011, and allowed the Syrian civil war to spiral out of control from 2011 on.