Peru has a stable government and tourism has boomed in recent years. With the added tourist dollars, the government has made a concerted effort to keep travelers and their valuables safe. There have been no terrorist attacks in Peruvian tourist areas in over a decade and the activities of the Shining Path are generally assumed to be isolated to a remote area of the Department of Ayacucho that most travelers would never visit.
Travelers should take the same precautions that they would in a major city in the US. Take common-sense precautions such as not going into unfamiliar areas alone, especially at night.
Petty theft is possible in busy tourist areas such as airports, markets, and other tourist sites, as it is in any city in the world, so be aware of your valuables and don’t leave them unattended. If you believe the Government warnings and Safety warnings in travel guides, they will scare you into never leaving your home. Just use common sense as you would in New York City.