Al Qaeda is building its most dangerous stronghold ever in the borderlands between Syria and Iraq. Hundreds of new jihadist fighters are flocking to this battlefield in the heartland of the Middle East. And with the civil wars in both countries all but certain to endure for the foreseeable future, the danger from this stronghold is growing.

It's an established and obvious point, a corollary to the famous post-Watergate principle that "it's always the cover-up, never the crime." The "crime" might initially seem serious, or at least embarrassing: sending the Watergate burglars to spy on Richard Nixon's Democratic opponents, whatever happened between Bill Clinton and Paula Jones or Monica Lewinsky. But of course what came after is what did the real damage.

I can pinpoint the exact moment when I realized Syria had turned into Mad Max. We were driving through Manbij, a small tumbleweed kind of town in the dusty northern outskirts of Aleppo province on a Friday afternoon during Ramadan, about a month before the August 21 chemical-weapons attacks that finally forced the international spotlight onto Syria’s two-year civil war.

The United States has quietly restarted security assistance to Pakistan, U.S. officials said on Sunday, after freezing much of that aid during a period of strained relations beginning with the 2011 Navy SEAL raid that killed al Qaeda chief Osama bin Laden. While the move to free up the aid has been underway for some months, it became public as President Barack Obama prepares for a White House meeting on Wednesday with Pakistani Prime Minister Nawaz Sharif.

Gao, the largest city in northern Mali, is a place of extremes. It’s a sprawl of one- and two-story mud-brick houses that lack power lines and running water, but it’s also home to the garish, McMansion-style estates of Cocainebougou, or “Cocaine Town,” a deserted neighborhood that once belonged to Arab drug lords who controlled the region’s smuggling routes for hashish and cocaine but fled, fearing reprisals from local citizens who blamed them for the Islamist invasion.

"I am French," explains the young man in the YouTube video carrying a Kalashnikov and wearing a kufiya cotton headdress as he sits in front of a waving black-and-white flag of al Qaeda. "Oh my Muslim brothers in France, Europe and in the whole world, Jihad in Syria is obligatory," says the fair-skinned youth with sandy hair, wispy beard and southern French accent, imploring viewers to join him and his younger brother in Syria.

"Quick, run, run," shouts Kurdish commander Roshna Akeed, as she orders two young female fighters to move toward a brick wall that represents the front line between Kurdish forces and al Qaeda-linked militants in this northern Syrian town. Six male Kurdish fighters are already guarding this part of the front. They have removed some of the bricks from the five foot-high wall, and their guns peak through small holes toward the enemy, which is positioned in a hamlet roughly one-third of a mile away.

Last week, it was brought to a lot of people's attention that al Qaeda were active on Twitter. This was slightly less surprising than it sounds. At a grassroots level, these early masters of the viral beheading video know social media's black magic well enough, which is probably why they decided to crowdsource ideas of how they could improve their online image.