British PM warns of Islamic State threat to UK

British Prime Minister David Cameron has warned of a possible Islamic State threat to the U.K., stressing the need for a "firm security response" to the militant group.
“If we do not act to stem the onslaught of this exceptionally dangerous terrorist movement, it will only grow stronger until it can target us on the streets of Britain,” reads a Sunday Telegraph article penned by Cameron. The Islamic State, which proclaimed a "caliphate" that straddles parts of Syria and Iraq, have driven an estimated 1.2 million Iraqis from their homes and have particularly targeted Turkmens, Ezidis, Shiite Muslims and Christians. Describing the group's ideology as "poisonous," "extremist" and "barbaric," the British PM said that the threat could not be prevented by "airstrikes alone."
"We need a tough, intelligent and patient long-term approach that can defeat the terrorist threat at source," he said.
Militants from the Islamic State, which already had control of parts of Syria, captured Mosul in June and then surged across northern Iraq, taking control of a number of predominantly Sunni cities.
The group seeks to establish an Islamic emirate ruled by an austere version of Islam in the Middle East, erasing national boundaries drawn by Europeans in the wake of World War I.
"This is a clear danger to Europe and to our security. It is a daunting challenge," said Cameron. "But it is not an invincible one, as long as we are now ready and able to summon up the political will to defend our own values and way of life ... That is how much is at stake here: we have no choice but to rise to the challenge."