Terrorism insurance is insurance purchased by property owners to cover their potential losses and liabilities that might occur due to terrorist activities.
It is considered to be a difficult product for insurance companies, as the odds of terrorist attacks are very difficult to predict and the potential liability enormous. For example the 
September 11, 2001 attacks resulted in an estimated $31.7 billion loss. This combination of uncertainty and potentially huge losses makes the setting of premiums a difficult matter. Most insurance companies therefore exclude terrorism from coverage in Casualty and Property insurance, or else require endorsments to provide coverage.
September 11, 2001 attacks resulted in an estimated $31.7 billion loss. This combination of uncertainty and potentially huge losses makes the setting of premiums a difficult matter. Most insurance companies therefore exclude terrorism from coverage in Casualty and Property insurance, or else require endorsments to provide coverage.On December 26, 2007, the President of the United States signed into law the Terrorism Risk Insurance Program Reauthorization Act of 2007 which extends the Terrorism Risk Insurance Act (TRIA) through December 31, 2014. The law extends the temporary federal Program that provides for a transparent system of shared public and private compensation for insured losses resulting from acts of terrorism.
The United States insurance market offers coverage to the majority of large companies which ask for it in their polices. The price of the policy depends on where the clients are residing and how much limit they buy.
Industry Needs
Concentration of risk is another factor in determining availability for terrorism insurance. Due to the concentrated losses of the World Trade Center, carriers were hit with large losses in one centralized location. Insurers seek to spread the coverage over a wider geographic area than as with other aggregate perils, such as flood.
Modeling the Risks
Insurance companies are using an approach that is similar to that used with natural catastrophe risks. A Swiss report suggested that in this case where demand is greater than the supply for terrorism coverage that a short-term solution is possible: a mix of government and private resource to make easy the transition. In this situation, the government would serve two functions: to establish rules to overcome the capacity shortage and to be the insurer of last resort.
