The boundary separating religion from politics has become ever more permeable in these volatile times. So when Pope Benedict XVI delivered remarks that included a medieval citation about Islam that was clearly inflammatory, a fiery response was precisely what he should have expected.

None of that excuses the violence that ensued or the threats of violence that continue. Sadly, there is a deep chasm in the fractious relations between the Christian and Muslim worlds.

The fact that some of these outbursts of rage come from extremist clerics does nothing to diminish the confusion between religion and politics. More moderate Muslims protest that murder and mayhem are not endorsed by Islam, but those protests are drowned out by the din of anti-Vatican demonstrations.

The pope's apology, while muted, was a historic departure for the Vatican. Still, throwing a match onto a pile of tinderwood, and then issuing even the most abject apology, won't douse any flames.

The pope said his comments were meant to renounce hatred and violence. What is needed now is a more sustained effort, by religious leaders on both sides of the divide.

It's disheartening that a church leader would make the ill-considered decision to quote a 14th-century Christian emperor's views of Islam as "evil and inhuman." The pontiff is a theologian and many did not hear the quote in the context of his speech to German university students. Still, the pope surely understands that as the world's Roman Catholic leader, his comments take on heightened importance and influence.

And while the Vatican decides how to move forward, diplomatic fence-mending must begin. Given that the pontiff plans a visit in November to the largely Muslim nation of Turkey, dispatching some olive branches to clerics there would be one rational starting point.