The Guardian reports: The US is facing its most daunting national security challenge in a generation after the European Union was plunged into “crisis” by Britain’s vote to leave, the head of the CIA warned on Wednesday.

John Brennan insisted that Brexit would not undermine cooperation with MI6 in the fight against terrorism, but suggested that the EU, a bulwark of peace and stability since the fall of the Berlin wall, would now be preoccupied with the UK’s departure.

“In the 36 years since I first entered government, I have never been witnessing a time with such a daunting array of challenges to our nation’s security,” Brennan told the Council on Foreign Relations in Washington. “Notable among those challenges is that some of the institutions and relationships that have been pillars of the post-cold war international system are under serious stress.

“Of all the crises the EU has faced in recent years, the UK vote to leave the EU may well be its greatest challenge. Brexit is pushing the EU into a period of introspection that will pervade virtually everything the EU does in the coming weeks, months and even years ahead,” he said. [Continue reading…]