International counter-terrorism efforts have reduced the ability of terrorist groups to mount large-scale attacks but have not been enough to downgrade the risk, according to a report by Aon.

The report, released last week, says that while the activities of established terrorist groups such as al-Qaeda are increasingly limited to “traditional conflict zones”, networks of local followers in Europe and North America continue to present a threat, as do an increasing number of nationalist terrorist groups.

These findings are based on Aon’s annual terrorism threat map, which is produced in collaboration with Janusian Security Risk Management and is based on global indications of terrorism threat including attacks, plots, communiqués and government counter-measures.

The map assesses the violent potential of terrorist groups in more than 200 countries and assigns a threat level to each country based on evidence of known active terrorist groups operating in the country, their aims and objectives, their track record of terrorist activity and operational capabilities.

Seven countries are identified as under “severe threat”: Somalia, Iraq, Palestine, Yemen, Afghanistan, Pakistan and India.

A further 19 countries are rated as having a “high threat” of terrorism, including the UK, Colombia, Israel, Nigeria, Russian, Saudi Arabia and Turkey.

The US is among more than 25 countries ranked at an “elevated threat” level including France, Germany, Mexico and Sudan.

Due to a number of recent terrorist incidents in the US, including the bomb scare in New York’s Times Square last month, the country is this year rated at a higher level within the elevated risk category.

Australia is ranked as a “guarded threat”, the second-lowest risk level.

Aon’s research indicates that challenges ahead in fighting global terrorism will include preventing terrorist groups establishing new bases in at-risk countries, as well as anticipating tactical innovations by terrorist groups.