Footage shows Iran has become more involved in the fight against ISIS. A recently released video shows an Iranian fighter plane attacking ISIS positions within Iraq. However, the Iranian government denies their involvement despite visual evidence and U.S. tacit acknowledgement.

Al Jazeera reports footage recorded on Nov. 24 shows an allegedly Iranian air force F-4 Phantom fighter jet attacking ISIS targets within Iraq. However, the Iranian government and military deny their aircraft are involved in the conflict.

"Iran has never been involved in any air strikes against Daesh targets in Iraq. Any cooperation in such strikes with America is also out of question for Iran," a senior Iranian official told Reuters on condition of anonymity, using an Arabic word for ISIS.

Similarly, Deputy Chief of Staff of the Iranian Armed Forces General Massoud Jazayeri told the Iranian state run news agency Fars that it is not cooperating with the U.S. and blamed the nation for what was happening.

"The Islamic Republic of Iran blames the United States as the root cause of unrests and problems as well as the terrorist actions of ISIL in Iraq," he said, blaming the U.S. and coalition for the destruction of infrastructure in both Syria and Iraq as well as for helping the terrorist group.

However, evidence points that the planes recorded are Iranian F-4s. According to Jane's Defense Weekly, the only two nations in the region to operate the F-4 are Turkey and Iran. Since Turkey has explicitly stated it will not partake in the coalition against ISIS, Iran is the only remaining possibility.

Iran already showed it picked sides when it became one of the first countries to help Iraq at the beginning of the ISIS crisis by giving them Sukhoi Su-25 ground attack planes.

U.S. officials reaffirmed the belief that Iran did launch airstrikes against ISIS despite the two adversaries having not formally and publically agreeing to join forces.

"We have indications that they did indeed fly air strikes with F-4 Phantoms in the past several days," said Pentagon spokesman Rear Adm. John Kirby, according to the BBC. "We are flying missions over Iraq, we co-ordinate with the Iraqi government as we conduct those. It's up to the Iraqi government to de-conflict that airspace. Nothing has changed about our policy of not coordinating military activity with the Iranians."

Nonetheless, both sides have an interest in Iraqi stability. Iran's Shiite government sees Baghdad as a friend and ISIS's Sunni extremists as dangerous to religious stability. The U.S. does not want the Middle East to deteriorate further. Both share the ultimate goal of defeating ISIS, so the old adage "the enemy of my enemy is my friend" applies in this instance.