Why Turkey is a vulnerable target to terrorist attacks

What was intel before Istanbul airport attack?
What was intel before Istanbul airport attack... 04:24

Turkish officials were quick to point fingers at the Islamic State of Iraq and Syria, or ISIS, for the triple suicide blasts at its largest airport in Istanbul that killed 41 people and wounded more than 270 others Tuesday. Still, no one has claimed responsibility.

Turkey was by no means a surprising target for a terrorist attack. According to CBS News senior security analyst Juan Zarate, the attack is the latest in a "tradition" of unclaimed Islamic attacks in Turkey. The former deputy national security adviser to President George W. Bush said the U.S. ally had been playing "footsie" with violent Islamic extremist groups within its borders, in part because of its geographical location.

"They're on the border with Syria, they're dealing with conflict and the refugee flows. You also have the fact that Turkey has been the thoroughfare for foreign fighters into Syria and into Iraq for a number of years and for some time," Zarate said. "They're now paying the price perhaps with those groups fighting and attacking within Turkey."

What's also clear is the attackers' rising new "methodology" in carrying out terrorist attacks. Turkish Prime Minister Binali Yildirim said the three attackers arrived at the airport in a taxi and blew themselves up after opening fire. They had grenades, suicide vests and automatic weapons.

"They certainly didn't penetrate the security, but they found obviously a point of vulnerability that we know exists in terms of airport traffic - that area before you reach security," Zarate said. "These individuals likely were not only well-armed but trained and certainly had coordinated before the attack and likely had planned this out for a number of weeks if not months."

The U.S. State Department had updated a travel warning about Turkey just one day before the attack in Istanbul, saying there were "increased threats from terrorist groups throughout Turkey." Zarate said this suggests intelligence officials saw "something that was troubling."

Fmr. Bush adviser: Turkey's response to Istan... 02:34

"The fact that they put out a new advisory demonstrating and saying that there are increased terrorist threats throughout Turkey and warning travelers certainly seems to suggest that there was additional information available to the U.S. government and certainly to the Turks," Zarate said.

As in Paris, Brussels and now Istanbul, Zarate warned that "without a doubt, ISIS is trying to find vulnerabilities, not just to attack in places like Iraq and Syria but well beyond into Turkey, Europe and even potentially North America."

But as Americans look forward to the July Fourth weekend - which is expected to hit record travel levels - Zarate assured people not to be concerned but to "be aware."

"Know where your exits are, know where your families are and certainly know how to communicate with authorities if you see something suspicious," Zarate said. "We can't let them win... and if they alter the way we operate in an open society, that's a victory for them."