Kissinger Warns Trump: ISIS Is Keeping Iran in Check, You Must Not Let Tehran Fill the Void

Former top U.S. diplomat Henry Kissinger has warned the Trump administration that Iran should not be allowed to fill the power vacuum that will be created when the Islamic State militant group (ISIS) is defeated.

In Iraq, Baghdad's forces have liberated the northern city of Mosul from the jihadi group and are close to ousting ISIS from all of its population centers. In Syria, a Kurdish-Arab coalition has recaptured almost half of the eastern Syrian city of Raqqa, which became the de facto ISIS capital after the group rose to prominence in mid-2014.

Now, the 94-year-old Kissinger, who served as secretary of state under Richard Nixon, has cautioned that defeating ISIS could lead to a "radical Iranian empire" across the Middle East.

"In these circumstances, the traditional adage that the enemy of your enemy can be regarded as your friend no longer applies. In the contemporary Middle East, the enemy of your enemy may also be your enemy. The Middle East affects the world by the volatility of its ideologies as much as by its specific actions," he wrote in an article last week for CapX.

"The outside world's war with ISIS can serve as an illustration. Most non-ISIS powers—including Shia Iran and the leading Sunni states—agree on the need to destroy it. But which entity is supposed to inherit its territory? A coalition of Sunnis? Or a sphere of influence dominated by Iran?

"The answer is elusive because Russia and the Nato countries support opposing factions. If the ISIS territory is occupied by Iran's Revolutionary Guards or Shia forces trained and directed by it, the result could be a territorial belt reaching from Tehran to Beirut, which could mark the emergence of an Iranian radical empire," he wrote.

Iran's elite Revolutionary Guards have been advising the Shiite-dominated Iraqi government and supporting Shiite militias, known as the Popular Mobilization Forces, working with Baghdad to liberate ISIS-held territories in the country.

In Syria, Iran is supporting the regime of President Bashar al-Assad alongside Russia. It has provided ground troops, tactical advisers and Shiite militiamen from countries such as Afghanistan to bolster the dictator's ranks.

Both Iran and the U.S. are working to degrade ISIS in the two countries, but the U.S. role is limited to special forces on the ground and a coalition of air forces bombing the jihadi group from above. Washington and Tehran rarely recognize the role of the other in combating the threat of ISIS and are avoiding any escalation between the two militaries.

This has not extended to the Assad regime. President Donald Trump in April authorized the first American strike against the Syrian government. The U.S. government accused the Syrian government of carrying out a chemical weapons attack against civilians. Both Syria and key ally Russia denied the allegations, despite witness testimony and soil samples gathered by Turkey that showed the presence of a chemical agent in the attack on the Idlib town of Khan Sheikhoun.

The Russian government said the Syrian military hit a weapons depot holding "toxic" weapons stored by militants. International powers, such as the U.S., Israel, Turkey, France and Britain, accused the Syrian regime of targeting civilians with chemical weapons.