Russia and Iran are using Ukraine and Israel as “battlefield laboratories” to probe at Western military vulnerabilities, experts told a House Foreign Affairs subcommittee Wednesday.

“Together, Russia and Iran are using Ukraine and the Middle East as battlefield laboratories to improve their weapons and develop techniques to overcome U.S. and allied defensive systems,” Dana Stroul, director of research at the Washington Institute, told lawmakers at a hearing on the “Despotic Duo.”

“Iran is extracting from Russia lessons in combined strike packages as well as insights into the strengths and weaknesses of Western-origin air and missile defense systems,” Stroul said in her written statement.