Both countries stepped up their support of the Taliban over the winter, possibly as a hedge against persistent American indecision about how deeply to stay involved, and for how long. Left unchecked, Russian and Iranian support could enable the Taliban to win the long-term occupation of a provincial capital this summer, which would further erode Afghan government legitimacy. To head off such an outcome, the new Trump administration must consider an approach that brought some success in the aftermath of the 2001 U.S. invasion: rebuilding a regional consensus with Russia and Iran—as well as China, India, Pakistan, and the Gulf states—to stop funding proxies and support stability in Afghanistan.

Russia’s support for the Taliban has altered the regional dynamic that fuels the war. Since the end of 2016, Russia has reportedly been providing arms to the Taliban operating in northern Afghanistan. Russian officials have also reportedly met with Taliban representatives in Russia and Tajikistan. Meanwhile, over the past year Moscow has held discussions with Islamabad and Tehran about their mutual interests in supporting the Taliban. Russia’s sudden cooperation with the Taliban is particularly surprising, given the bloody fighting between their Soviet and Mujahedin predecessors in the 1980s.

Russia claims that its motivation for supporting the Taliban is to fight the Islamic State’s Afghan offshoot, prevent Central Asian terrorist groups such as the Islamic Movement of Uzbekistan (IMU) from destabilizing the region, and control drug trafficking through Central Asia into Russia. But the real reason may be to cause trouble for the United States.

Although there are indeed foreign fighters in northern Afghanistan, the threat is overblown and the Russian response is counterproductive. The main reason that foreign terrorist groups can operate in Afghanistan is the cover provided by the chaos from the Taliban insurgency. Last week’s Taliban attack in Mazar-i-Sharif only heightens this risk. Rather than funding the Taliban, the Russian government should be supporting Kabul as it tries to regain control of territory from the Taliban, IMU, and ISIS.

Iran has a similar rationale for increasing its support of the Taliban, which traditionally has been its enemy. Since 2014, it has given weapons to Taliban groups near the Iranian border, in part to keep ISIS at bay. Iran has also quietly allowed Taliban offices to operate within Iran. Taliban leader Akhtar Mansour was killed by a U.S. drone strike in May 2016 as he returned to Afghanistan from Iran, where he had apparently stayed for two months. Iran also is wary of a continued U.S. military presence in Afghanistan, which it fears could be used to launch strikes in the event of hostilities over Iran’s nuclear program. Beyond that, Iran lacks confidence that the joint NATO-Afghanistan plan for ending the insurgency will work, or even do much to mitigate the risks Iran faces from terrorism, refugee flows, and drug trafficking as the war continues.

Iran’s support to the Taliban could be reversed, however, with assurances about a long-term plan for ending the insurgency and a commitment not to use Afghan soil for attacks against Iran (or other neighbors). After all, Iran’s religious ideology is at odds with the Taliban’s, and the country was an early ally of the United States during the 2001 negotiations to establish a new government in Afghanistan.

Iran, Russia, and the United States all share essentially the same interests in a peaceful and stable Afghanistan.

To be sure, Iranian and Russian support for the Taliban would not be strategically significant without Pakistan’s much greater support for the Taliban. That support includes money, weapons, training, and free movement within Pakistan. Ending Pakistan’s support for the Taliban is a complex task that will not be quickly resolved. But the negative impact of Pakistan’s support for the Taliban could be blunted by a strong regional consensus that pressures Pakistan to reduce its support.

In theory, that consensus shouldn’t be so difficult to reach. Iran, Russia, and the United States all share essentially the same interests in a peaceful and stable Afghanistan. That was the premise under which the three nations worked side by side when developing the Bonn Agreement in 2001. Re-forming that alliance should be a centerpiece of a revised U.S. strategy for Afghanistan.

To begin with, the United States should clarify that its primary objective in Afghanistan is a peaceful and stable nation. Beyond that, together with its allies, the United States must articulate a credible commitment to providing the military, diplomatic, and economic support needed over time to achieve that goal. Such a declaration would help allay persistent fears that the United States could rapidly withdraw assistance to Afghanistan, as it did in 1991, and spur another civil war that Afghanistan’s neighbors would need to deal with. At the same time, the United States should emphasize that its troop presence in Afghanistan is negotiable if the transnational terrorist threat ends and the Afghan government no longer needs as much support.

Second, the United States should provide additional military support to quash the expected Taliban summer offensive. The Afghan National Security Forces need the capacity to prevent further Taliban gains to convince neighboring countries that the Taliban will not win and that they should place their chips with the Afghan government.