Ignoring threats posed by the Islamic State of Iraq and Syria (ISIS) would be shortsighted and foolish, British Prime Minister David Cameron told members of Parliament Wednesday.

“I disagree with those people who think this is nothing to do with us and if they want to have some sort of extreme Islamist regime in the middle of Iraq that won’t affect us – it will,” Cameron said.

ISIS, he warned, plans to attack British soil. Consequently, Cameron said working to stabilize governments in places like Iraq, Somalia, Nigeria and Mali where jihadist insurgencies are is of the utmost importance.

An estimated 400 British nationals fighting in Syria present a “particular risk” to the U.K. if they return home, said British Foreign Secretary William Hague. Many of those British nationals are fighting for ISIS.

“The government’s own figures show more UK citizens are joining ISIS than signing up for the Armed Forces Reserves. This is shameful, embarrassing and will cause deep concern,” said MP Vernon Croaker, the shadow defense minister.

ISIS has taken its propaganda recruiting campaign to social media where it has posted English-language videos calling Muslims from around the world to jihad.

One such video posted Thursday features a British Muslim fighter, speaking under the nomme de guerre Abu Bara’ al-Hindi, telling people to open the Quran and read the verses about jihad, then give up what they have and join the fight.

“Are you willing to sacrifice the fat job you’ve got, the big car you’ve got and the family you have?” al-Hindi asked. “If you are going to sacrifice this for the sake of Allah … then Allah will give you 700 times more.”

Britain is not alone in worrying about the current escalating crisis in Iraq. Australia this week warned jihadists looking for refuge in Australia to stay away. Immigration Minister Scott Morrison told jihadists he will tear up their visas. An estimated 300 Australians have traveled to join the jihad in the Middle East, with many believed to be trying to join ISIS. About half of them have been identified, and reports say the Australian government has begun to void their passports.

“I don’t want anyone to think this is just a difficulty in a far away country that has no consequences of its own,” said Australia’s Prime Minister Tony Abbott.