As yesterday's terror wave instructs us, Iraq has joined the regional civil war pitting Sunnis against Shiites (or kindred sects like the Alawites).
A coordinated terror campaign killed over 100 people, mostly Shiites, and wounded hundreds in 21 separate bombings throughout Iraq.
The collapse of the power-sharing arrangement between Shiites, Sunnis and Kurds was signaled when Iraqi Vice President Tariq al-Hashemi was sentenced to death in absentia. He is charged with being the mastermind of the Sunni death squads who carry out attacks primarily against the Shiites. There is little chance that the sentence will be carried out as al-Hashemi enjoys the protection of Sunni regional power, Turkey.
One of the American successes in Iraq was to temporarily win over the Sunnis, who formed the backbone of support for Saddam Hussein. They enlisted the Sunni tribes against Al Qaeda with a measure of success and appeared to have pacified the Sunni triangle. The Americans are gone, now that President Barack Obama, to the applause of the Democratic National Convention, has "ended the war" in Iraq.
It was perhaps too much to expect that Iraq could remain aloof from what was transpiring across the border in Syria. Iraqi air space is being used by Iran to resupply the Assad regime in Syria and transport Iranian forces who are trying to help the Assad regime suppress the insurgency there.
Al Qaeda forces that Assad had allowed to infiltrate into Iraq to harass the Americans have headed back into Syria to fight him. Shiite Muslims from Iraq are moving into Syria to aid Iran in assisting the Assad regime, while the Kurds in both countries are attempting to exploit opportunities and ward off threats. Lebanon is on the brink of joining the fray as well.
The only way that one can avoid becoming engulfed in a neighboring civil war is by imposing strict neutrality laws. During the wars of the French Revolution, the US sought to prevent the involvement of its citizens on either the French or British side. France sought, together with Britain, to impose neutrality in the Spanish Civil War, fearing that to do otherwise would risk a French civil war, given the high polarization of French society. That policy became a farce, given the intervention by fascist Italy and Nazi Germany .
In Europe and the United States, one was dealing with national governments and sovereign states, whose borders meant something. In the Middle East or in Africa, national borders count for very little and civil wars tend to engulf the entire neighborhood.