British Prime Minister spoke this morning right after the country raised its terror threat level to "severe" in the face of the growing dangers posed to the West by ISIS.

"This is not some foreign conflict thousands of miles away that we can hope to ignore. The ambition to create an extremist caliphate in the heart of Iraq and Syria is a threat to our own security here in the UK. And that is in addition to the many other Al Qaeda inspired terrorist groups that exist in that region. The first ISIL terrorist attacks on the continent of Europe have already taken place. We now believe that at least 500 people have traveled from Britain to fight in Syria and potentially Iraq," he said.

Last week it emerged that the main suspect in the beheading of American journalist James Foley had traveled from London to join ISIS.

"Now we cannot appease this ideology. We have to confront it at home and abroad. To do this we need a tough, intelligent, patient, comprehensive approach to defeat the terrorist threat at its source. Tough, in that we need a firm security response - whether that is action to go after the terrorists, international cooperation on intelligence, and counterterrorist or uncompromising measures against terrorists here at home."

LONDON (AP) -- Britain's Home Secretary Theresa May says the country has raised the terror threat level from substantial to severe, but says there is no specific threat.

The threat level means that a terrorist attack is considered "highly likely," but May insisted Friday there is no information to suggest an attack is imminent. She says higher threat level is related to developments in Iraq and Syria.

Severe is the second-highest threat level.

May says the decision by the Joint Terrorism Analysis Center is made on the basis of intelligence and is independent of government.

Britain has repeatedly expressed concern about British nationals traveling to the Middle East and returning to wage attacks in the U.K.

Martha MacCallum discussed the new developments with FoxNews.com digital politics editor Chris Stirewalt. They compared Cameron's words today to President Obama's statement on Thursday that there is "no strategy" right now for dealing with ISIS. 

Stirewalt said Cameron was direct and straightforward in answering questions, while President Obama tends to put out a "word salad" in an effort to avoid giving straight answers.

He also noted that Cameron is not blaming the chaos in Iraq and Syria on the U.S.-led war in Iraq under George W. Bush and his predecessor Tony Blair.

Stirewalt said the phrase 'war on terror' is a "cop-out" because a country cannot really go to war against a "methodology of fighting." He said the West has been "cringe-y" in talking about fighting radical Islamists who seek to impose the religion on people.

Stirewalt interpreted Cameron's strong words as a "prodding" toward Obama to take further military action against ISIS in Syria and Iraq.

Watch the full discussion above.