Amnesty International (AI) released a 44-page report Dec. 7 on the Islamic State's “substantial arsenal of arms and ammunition.” According to the human rights group, the inventory comprises weapons designed or manufactured “in more than 25 countries,” including the United Kingdom, the United States, Russia, China, Germany and France.

The findings come as no surprise to arms-tracking organizations that have been monitoring IS weaponry for years, among them the Geneva-based Small Arms Survey and the British Conflict Armament Research (CAR). Studies conducted by these nongovernmental organizations in Iraq and Syria indicate that IS benefits from a large array of supply sources.

Although IS militants can rely on well-stocked Iraqi black markets, their main access to firepower has been the battlefield, where they have systematically captured their enemies' weaponry after defeating them.

Al-Monitor spoke with a CAR investigator who describes the range and scope of weapons streaming into the jihadists’ stockpiles as “astonishing.” For this researcher, who requested anonymity for security reasons, the goal is now to connect the dots.