Current Issues for Syria’s Chemical Weapons and Nuclear Weapons Programs

Current Issues for Syria’s Chemical Weapons and Nuclear Weapons Programs

Current Issues for Syria's Chemical Weapons and Nuclear Weapons Programs

Updated September 11, 2025 (IN12480)

On December 8, 2024, the government of Syria's Bashar Al Asad collapsed following armed offensives led by the Hay'at Tahrir al Sham (HTS) coalition. A successor government inherited unresolved international concerns about the Asad regime's chemical and nuclear weapons programs. Those programs violated Syria's obligations under the Chemical Weapons Convention (CWC) and the Nuclear Nonproliferation Treaty (NPT)—obligations to which a new Syrian government will be subject. The Asad regime was not in compliance with these obligations, according to congressionally mandated reports from the U.S. government and multiple international monitoring organizations. The new government, under interim President Ahmed Al Sharaa, has pledged to follow through with this and has taken initial steps to cooperate with international inspectors. Secretary of State Marco Rubio said in May 2025 that the Syrian government asked for U.S. assistance to identify sites and remove weapons of mass destruction from the country, and that the United States was "willing to provide it."

Chemical Weapons

Syria's chemical weapons program, which began in the 1970s, became an acute source of international concern in August 2013 after the government attacked civilians with chemical weapons. That same month, President Obama requested congressional authorization for the use of military force against Syria; the Senate subsequently considered a joint resolution authorizing such an action. President Obama asked congressional leaders in September 2013 to postpone a vote on the measure in order for the United States to pursue a diplomatic initiative based on a Russia-brokered agreement. Under this agreement, Syria agreed to accede to the CWC, which obligates parties to declare and destroy all chemical weapons stocks and production facilities. Following the government's October 2013 CWC accession, Syria declared tons of chemical warfare agents and the international community oversaw the removal and destruction of these agents. Later, the Asad government used both chemical weapons and toxic chemicals in dozens of attacks on Syrian civilians.

The Organization for the Prohibition of Chemical Weapons (OPCW), which monitors states' CWC compliance, has been unable to verify the Syrian declaration's completeness. The United States, the OPCW, and other governments have long assessed that Syria has not declared all of its chemical weapons stocks and facilities to the organization. In a December 12, 2024, statement, OPCW Director-General Ambassador Fernando Arias explained that Syria's declaration "still cannot be considered as accurate and complete" and that Syria may possess "potential new components of a chemical weapons programme."

The OPCW, the United States, and other governments have stated that Syria's new government should secure and destroy the remnants of Syria's chemical weapons program. A December 14 joint statement from the United States and a number of other governments "stressed" the need for Syria to "secure and safely destroy chemical weapons stockpiles." In his December statement, Arias identified two related tasks for the OPCW: (1) to "prevent proliferation and any further use" of Syrian chemical weapons, and (2) to "protect and maintain documents, evidence, and witnesses related to" the previous regime's chemical weapons program.

HTS officials have stated that the group will not use any remaining Syrian chemical weapons, and that they are coordinating with international organizations to identify, secure, and dismantle chemical weapons sites. The OPCW Director General visited the country in February to conclude a nine-point action plan for future cooperation. Several OPCW investigatory missions have visited Syria since then. In a speech at the OPCW in March, Syria's interim foreign minister emphasized that the Syrian people were victims of the Asad regime's chemical weapons attacks. He expressed the new government's "commitment is to dismantle whatever may be left from it, to put an end to this painful legacy and ensure Syria becomes a nation aligned with international norms." The Syrian authorities have informed the OPCW that they lack the necessary knowledge for identifying "what elements of the Syrian chemical weapons programme have not been declared," and that the OPCW will need to "visit and assess more than 100 additional [Syrian] locations," to include "military facilities, airfields, and research centres, all of which may be in varied, and hazardous, states of disarray, damage, or destruction." The OPCW is raising funds from member states to support this effort, which may include on-site destruction and verification.

Nuclear Program

The International Atomic Energy Agency (IAEA) began investigating undeclared Syrian nuclear activities after a 2007 Israeli air strike destroyed a Syrian structure that, according to U.S. and Israeli assessments, was a nuclear reactor under construction as part of a Syrian nuclear weapons program. An April 2024 State Department report notes that "undeclared nuclear material might exist in Syria." Pursuant to Syria's NPT obligations, Syria has a comprehensive IAEA safeguards agreement, which the country ratified in 1969. Such agreements empower the agency to monitor declared nuclear facilities, as well as to detect undeclared nuclear activities and material.

Beginning in 2011, Syria refused to cooperate with the IAEA investigation. The Asad regime reversed this stance in March 2024. Following June 2024 "technical discussions" between Syrian and agency officials, the government permitted IAEA inspectors to visit three locations and collect environmental samples. Subsequent IAEA analysis of samples taken from one of these locations "revealed a significant number of natural uranium particles … of anthropogenic origin." The IAEA took additional samples from this location in June 2025 and, according to Grossi, will evaluate the sampling results as part of the agency's efforts to "clarify and resolve the outstanding safeguards issues related to Syria's past nuclear activities and to bring the matter to a close."

Selected U.S. Nonproliferation Programs

A senior U.S. official told reporters on December 9, 2024, that the United States has "good fidelity on" the status of Syria's chemical weapons. The United States "will work with" Syrian officials, international organizations, and other governments to find, secure, and dispose of "any nuclear, radiological, biological or chemical weapons material," Deputy National Security Adviser John Finer stated on December 19, 2024.

Congress has given the executive branch authorities to be used in such cases to address acute proliferation risk. The Departments of State and Defense have authorities and funds that, notwithstanding other legal restrictions, may be used for the U.S. government to perform certain work in Syria, such as securing or removing material related to Syria's chemical or nuclear weapons programs.

The State Department's Nonproliferation and Disarmament Fund (NDF), as authorized by Section 504 of the Freedom Support Act (P.L. 102-511) and annual appropriations laws, may use funds anywhere in the world, notwithstanding other restrictions. The Department of Energy's National Nuclear Security Administration has previously provided expertise and in-kind contributions, such as technology, to NDF projects. Similarly, the Department of Defense may use funds from DOD's Cooperation Threat Reduction (CTR) Program in response to urgent proliferation threats (P.L. 113-291). The executive branch has waived the application of terrorism-related legal restrictions on the use of some funds in Syria for counterterrorism purposes, and could possibly do so for counterproliferation reasons. Congress may wish to oversee the use of these programs in the current context.