If you’re invested in the question of whether Syria has used chemical weapons on its own citizens, you’ve been exposed to a range of terms like "soil samples," "witness interviews," "dilated pupils," and "urine samples." For most laymen, it’s not clear which piece of evidence is more reliable than the other. But the question couldn’t be more important given allegations by France, Britain, and now Israel that Syrian forces have deployed chemical weapons — an act that would constitute a "red line" for the United States if true. Since all evidence is not created equal, we asked international chemical weapons consultant Ralf Trapp about the various investigative techniques cited in the case of Syria — and their value.
Pictures of victims whose mouths are frothing and pupils are dilated
This evidence was cited today by Brig. Gen. Itai Brun, the chief of research and analysis for the Israeli army’s military intelligence division. "The dilated pupils, the frothing at the mouth and other signs testify, in our view, to the use of liquid chemical weapons, some kind of liquid chemical weapons, apparently sarin," said Brun. The quality of this evidence depends on a range of factors: Who took the pictures, how many pictures there are, how old the victims are, and whether the images are authentic. At the moment, it’s not clear how many images the Israelis have seen, and it’s very difficult to determine anything conclusively with a small number of images, said Trapp. "A small number of pictures from victims is an important lead, but isn’t in itself evidence," he explained.
France and Britain say soil samples support charges that Syria used nerve agents in Aleppo, Homs, and possibly Damascus. According to Trapp, collecting soil samples is a reliable technique because chemical agents can remain in soil for a long time. The question in this case is: Was the sample protected from interference? The ideal scenario is if a soil sample is collected, packaged, and protected from outsiders, but little is publicly known about how the soil was collected in Syria.
No one has cited urine samples as evidence of chemical weapons use in Syria yet, but the CIA has requested urine samples from Syrian rebels, according to the New York Times. While this technique can be useful because certain biomarkers will appear in the urine of victims, it’s recommended that the test be conducted within two days of the incident or a test could result in a false negative. Blood tests can also be useful, but are more difficult because they require a physician to draw the blood and the consent of the victim.
The French and British have also cited "witness interviews," which can be valuable but rely crucially on how the interview is conducted. It’s important to query a range of witnesses and compare the testimonies to each other for corroboration or contradiction. It’s also important to avoid leading questions. If Trapp was assigned to Syria, he’d ask the witnesses simples questions: What happened? When did it happen? What did you see, hear, and smell?
The CIA is also seeking out hair samples, which can be useful because evidence can remain in the hair for a long time. Obviously, it’s important to authenticate the individual and the context in which they were exposed before using the sample as evidence.
While each of the above pieces of evidence has value, Trapp adds that an optimal piece of evidence would be a chemical artillery shell discovered in the field. Thus far, that hasn’t happened, which explains the reliance on other indicators.
Josh Rogin covers national security and foreign policy and writes the daily Web column The Cable. His column appears bi-weekly in the print edition of The Washington Post. He can be reached for comments or tips at firstname.lastname@example.org.
Previously, Josh covered defense and foreign policy as a staff writer for Congressional Quarterly, writing extensively on Iraq, Afghanistan, Guantánamo Bay, U.S.-Asia relations, defense budgeting and appropriations, and the defense lobbying and contracting industries. Prior to that, he covered military modernization, cyber warfare, space, and missile defense for Federal Computer Week Magazine. He has also served as Pentagon Staff Reporter for the Asahi Shimbun, Japan's leading daily newspaper, in its Washington, D.C., bureau, where he reported on U.S.-Japan relations, Chinese military modernization, the North Korean nuclear crisis, and more.
A graduate of George Washington University's Elliott School of International Affairs, Josh lived in Yokohama, Japan, and studied at Tokyo's Sophia University. He speaks conversational Japanese and has reported from the region. He has also worked at the House International Relations Committee, the Embassy of Japan, and the Brookings Institution.
Josh's reporting has been featured on CNN, MSNBC, C-Span, CBS, ABC, NPR, WTOP, and several other outlets. He was a 2008-2009 National Press Foundation's Paul Miller Washington Reporting Fellow, 2009 military reporting fellow with the Knight Center for Specialized Journalism and the 2011 recipient of the InterAction Award for Excellence in International Reporting. He hails from Philadelphia and lives in Washington, D.C.| The Cable |
Colum Lynch is Foreign Policy's award-winning U.N.-based senior diplomatic reporter. Lynch previously wrote Foreign Policy's Turtle Bay blog, for which he was awarded the 2011 National Magazine Award for best reporting in digital media. He is also a recipient of the 2013 Elizabeth Neuffer Memorial Silver Prize for his coverage of the United Nations.
Before moving to Foreign Policy, Lynch reported on diplomacy and national security for the Washington Post for more than a decade. As the Washington Post's United Nations reporter, Lynch had been involved in the paper's diplomatic coverage of crises in Afghanistan, Iraq, Lebanon, Sudan, and Somalia, as well as the nuclear standoffs with Iran and North Korea. He also played a key part in the Post's diplomatic reporting on the Iraq war, the International Criminal Court, the spread of weapons of mass destruction, and U.S. counterterrorism strategy. Lynch's enterprise reporting has explored the underside of international diplomacy. His investigations have uncovered a U.S. spying operation in Iraq, Dick Cheney's former company's financial links to Saddam Hussein, and documented numerous sexual misconduct and corruption scandals.
Lynch has appeared frequently on the Lehrer News Hour, MSNBC, NPR radio, and the BBC. He has also moderated public discussions on foreign policy, including interviews with Susan E. Rice, the U.S. National Security Advisor, Gerard Araud, France's U.N. ambassador, and other senior diplomatic leaders.
Born in Los Angeles, California, Lynch received a bachelor's degree from the University of California, Berkeley, in 1985 and a master's degree from Columbia University's Graduate School of Journalism in 1987. He previously worked for the Boston Globe.| The Cable |