Who is #1 arms exporter?

Worldwide trade in arms is estimated to be worth about $100bn per year. A defence industry think tank says that major weapons sales in the five years to 2017 were ten percent higher than in 2008 to 2012. The United States is the world's number one arms exporter, accounting for about 34 percent of global arms sales. The US's arms exports are 58 percent higher than those of Russia, the world's second-largest exporter. 

In 2014 the Arms Trade Treaty (ATT) came into force, with the aim of regulating the international trade in conventional weapons. It requires states to monitor arms exports, and ensure that their weapons sale don't break existing arms embargoes, or end up being used for human-rights abuses, including terrorism.