Such war would not only destroy Iraqis' hopes in stability and prosperity, it would also bury every aspiration in the region for pluralism and reform—the Iraqi example could be used then as call for accepting dictatorship or going back to the Salafi origins as an easy alternative for a change that leads to civil war.
Despite there have been some attempts to seize the chance and build on the emotions in the aftermath of the attack it seems that the effect is much less pronounced than what we experienced after the first attack last year and results are not going to be as spectacular as the perpetrators were hoping. Still this point, attacking shrines, would remain an issue that can spark violence and widen the gap among the people.
What made write about this today is an intersting article I saw that was written by an Iraqi author in which he outlined an unlikely yet truly scary scenario. You can read it here if you know Arabic but if you don't his point can be summarized by the following; he's saying that as long as there are attempts to ignite civil war through attacking shrines then we really should expect a large-scale incident that would make the entire Shia world shake and end any chance for peace in Iraq, that is attacking the Shrine of Imam Hussein.
This particular shrine is more important spiritually and emotionally than the shrine of Hussein's father Imam Ali. It represents the history of Kerbala and the legendary revolution of Hussein and his companions which is the most revered event in the history of Shia Islam. Any act against this place could lead to incontrollable chaos in Iraq. The author says such an attack is not unlikely because actual undercover control in Kerbala is in Iranian hands and perhaps the highly organized attack on the joint provincial coordination center on January 20 gives an idea about the depth of Iran's influence in the city and the force that protects the shrine is very likely to be infiltrated as well.
And then Kerbala would make a more logical target than Najaf because of its proximity with the al-Qaeda triangle and al-Qaeda did in fact carry out several operations in the vicinity of Kerbala which means it would be easy for Iran and its surrogates to deny involvement in operation and blame it on Sunni extremists. Actually regardless of who pulls the trigger such an operation could only happen with Iranian orders and consent.
What increases the fear that this scenario could be actually in the works is a senior Sadr's aide recent statement in which he alluded to close cooperation between al-Qaeda and Iran.
I hope the author is wrong but at the same time I see a need to double the effort to prevent further attacks on major Shia and Sunni shrines and make that part of the overall security plan. Assigning trust-worthy vetted forces can spare us the headache of thinking about the possible tragic effects of another bombing and from the worse possibility of dealing with them.
Update: Kerbala governor feels the danger too, from Radio Saw:
Kerbala governor Aqeel Khazali pointed out the intent of security authorities to enforce additional security measures in the light of intelligence reports speaking of possible attacks on shrines in Kerbala. Khazali cautioned that any attack on these shrines would ignite sectarian war at not only the local level but at the regional and Islamic world levels.
The governor rejected demands by the locals to relax the security restriction imposed in the city adding that the danger of having shrines targeted is based on verified intelligence reports.