Russia can’t be trusted to be an ally in the fight against terrorism because that nation’s leaders seek to undermine the U.S. at every turn, experts warned Congress.

Four experts testified Tuesday to a House subcommittee on whether Russia can be counted on as a counterterrorism partner or if they are “fanning the flames.”

Only one of the four, Simon Saradzhyan, the director of the Russia Matters Project, advocated for partnering with Russia when both nations’ counterterrorism goals aligned, saying it would save lives.

The other three, Colin Clarke with the RAND Corporation, Svante Cornell, director of the Central Asia-Caucasus Institute, and Michael Carpenter, a senior director of the Biden Center for Diplomacy and Global Engagement, cautioned against any such alliance.

“Russia’s main aim is to undermine U.S. leadership in the world, and when terrorists share that aim, they have no problem supporting and manipulating them,” Cornell said.

But, Saradzhyan said that Russia could be an effective partner, especially when both countries seek to prevent non-state actors from acquiring nuclear weapons.

Congress members asked specifically about work being done by both the United States and Russia in Syria and Russia’s involvement with Iran.

“Let’s not fool ourselves. Partnering with Russia in Syria would be the same as partnering with Hezbollah or Iran,” Carpenter said.

He added that Russia in Syria coordinates their actions with Hezbollah, a terrorist organization supported by Iran. Through this partnership, Hezbollah fighters have gained military tactical experience and equipment for future fighting.

Rep. Brian Mast, a Florida Republican and Army veteran who served in Afghanistan, asked whether Russia would allow the estimated 5,000 Russians fighting with the Islamic State back into their country.

“Absolutely not,” Clarke said. He described how Russia practically ushered the fighters, mostly Chechen, to Syria, knowing that Russian air force planes could then bomb them in Syria and tighten border controls to keep them from re-entering Russia.

Outside of the Middle East and its own borders, Rep. Robin Kelly, D-Illinois, asked if Russia could be counted on to help with North Korea.

Saradzhyan said they could, mostly to constrain the number of nuclear-armed states near its borders.

But Cornell said that Russia would take any measure to foment chaos for the United States and could easily become North Korea’s main “pipeline” of support should China back away from that role.

Mast and others asked for examples of what the United States should not do regarding counterterrorism work with Russia.

“I would not want the U.S. government to share any information that could compromise sources or methods used against dissidents inside Russia,” Carpenter said. “I certainly would not want the U.S. military to engage in combat operations or share information on targets, making them complicit in Russia bombing campaigns.”

Those bombing campaigns were characterized by multiple experts as disregarding civilian casualties and in keeping with Russian “scorched earth” tactics when fighting either counterterrorism or counterinsurgency operations.