Stanford's International Travel Policy references the US Department of State Travel website which issues travel warnings and travel alerts for travelers. Familiarize yourself with the risks of travel in the particular countries and/or regions to which you are traveling.
The U.S. Department of State has released its new tool, iPhone App Smart Traveler, designed to provide easy access to frequently updated official country information, travel alerts, travel warnings, maps, and U.S. Embassy locations.
While this website refers to the U.S. government’s ability to assist Americans in a particular country, the conditions it describes often affect anyone traveling there. You should also check your embassy’s website in that country for information specific to you.
Another excellent source of information is the Overseas Security Advisory Council’s website on Global Security News & Reports. You can register with this website to sign up for country and regional travel alerts.