Cameron vows to hit 'poisonous ideology of Islamist extremism'

British Prime Minister David Cameron on Monday said his country would start to address the root causes of the Islamic State's rein of terror — specifically, "Islamist extremism," a term President Obama has been hesitant to use.

In a Facebook post Monday, Cameron said his government would launch a series of new steps to protect UK citizens at home, and force ISIS into a retreat abroad.

"This includes a real focus on tackling the causes of the threats we face – not just their consequences," he said. "So we will tackle the poisonous ideology of Islamist extremism and refocus our aid budget to support fragile and broken states and regions, to prevent conflict and promote the golden thread of conditions that drive prosperity across the world: the rule of law, good governance and the growth of democracy."

The conservative leader of the UK also warned the Islamic State against making any move to export a Paris-style attack to his country, and indicated he would encourage the use of deadly force against any who try.