What he should have done: investigated the Benghazi incident seriously and honestly (his choice for chief investigator, former State Department hack Thomas Pickering, is an opportunist who will write whatever the White House wants), got those responsible, and made sure that nothing like that ever happens again. Perhaps an apology to the families of those killed would be in order.
What he did: pushed the “peace process” for two years, though then he did get the idea it wouldn’t work. He also opposed, albeit starting far too late, Palestinian Authority (PA) unilateral statehood bids. But will he continue that revised policy into a second term?
What he should have done: realized the peace process isn’t going anywhere, and understood that’s because of PA intransigence and the Hamas challenge that is radicalizing even further Palestinian policy. When the PA subverts U.S. policies, he needs to be willing to pressure and criticize it.
What he did: said he supported the rights of Christians and women from (Islamist) repression. But he never did anything about it. Zero. He cozied up to Syria and Iran at the very moment they were violently suppressing dissidents at home and opponents abroad.
What he should have done: genuinely worked to protect the rights of Christians and women as well as the lives of moderates by using leverage.
What he did: said that al-Qaeda was defeated.
What he should have done: understood that al-Qaeda is not finished by any means. And its partner the Taliban is still going strong. But this issue made less difference, since U.S. policy did fight al-Qaeda anyway.
What he did: continued the withdrawal from Afghanistan and tried to cut a deal with the Taliban.
What he should have done: continued the withdrawal from Afghanistan, but followed a realpolitik policy and set into place a strong set of patron-client relationships with those willing — albeit for their own interests — to keep the Taliban from taking power. The problem is that once U.S. forces are out, the regime is likely to collapse and possibly give way to a revolutionary Islamist, anti-American government.
What he did: although the U.S. government conducted drone strikes and the killing of Osama bin Laden, unilaterally, it generally continued to pour money into Pakistan despite its lack of cooperation, activity as a major sponsor of terrorism, and institutionalized anti-Americanism, persecution of Christians, and support of radical Islamist ideology.
What he should have done: moved away from Pakistan and rebuilt relations with India.
What he did: forbade an honest discussion of the enemy and threat in the U.S. military; minimized or denied that attacks like the one at Fort Hood were terrorist attacks.