In 2015, the highest ranking conflict prevention priority for U.S. policymakers will be the intensification of the crisis caused by the Islamic State group in Iraq and Syria, a survey conducted by the Council on Foreign Relations found.

The foreign policy think-tank group's Center for Preventive Action (CPA) invited more than 2,200 government officials, academics and foreign policy experts to rank a list of potential conflicts based on their perceived effects on U.S. interests and likelihood of occurring in 2015.

"Out of ten priority contingencies, respondents rated only one - the Iraq crisis - as both highly probable and highly consequential," the report said. The second highest rated event worrying policymakers was a large-scale attack on U.S. soil or ally, followed by a cyber attack on critical U.S. infrastructure.

"The Preventive Priorities Survey is unique in providing a forward-looking assessment of the specific crises and conflicts that really worry U.S. foreign policy experts," said CPA Director Paul Stares. "This is invaluable to focusing U.S. policymakers' attention and resources on the most important conflict prevention challenges."

Another high priority event, an armed confrontation in the South China Sea between China and other Southeast Asian countries, was upgraded from a low chance of happening to moderate.

The two new priority scenarios appearing on this year's survey were the escalation of both the Ukraine-Russia crisis and the Israeli-Palestinian tensions.

"Both were deemed highly likely to occur, but with moderate effects for the United States," the report said.

According to the council, the top ten U.S. conflict prevention priorities in 2015 are as follows:

-The intensification of the conflict in Iraq
-A large-scale attack on the U.S. homeland or ally
-A cyberattack on U.S. critical infrastructure
-A severe North Korean crisis
-The renewed threat of Israeli military strikes against Iran
-An armed confrontation in the South China Sea
-The escalation of the Syrian civil war
-Rising violence and instability in Afghanistan
-Increased fighting in eastern Ukraine
-Heightened Israeli-Palestinian tensions

A November Gallup poll asked Americans what they thought the most important problems facing the country were. The top three answers were the economy (20 percent), dissatisfaction with the government (19 percent), and illegal immigration (13 percent). Out of the 13 issues to choose from, terrorism appeared in 9th place with 4 percent, and the Islamic State crisis appeared in 11th place with 3 percent.