This sentence should cause a lot concern about Iran taking over Iraq

A disturbing sign of Iran's growing influence in Iraq and beyond was highlighted on March 8 during a seminar titled "The Iranian Identity," Bloomberg View reports.

"Iran is an empire once again at last, and its capital is Baghdad," said Ali Younusi, an advisor to Iranian Supreme Leader Khamenei.

Iraq, particularly the eastern and southern regions of the country with a majority Shia population, has tended to fall within the orbit of Iran's influence. During the Iran-Iraq war (1980-1988), Iran funded Shiite militias with the aim of overthrowing Saddam Hussein's government.

Ultimately, the two countries ground each other into a stalemate. However, following the American invasion and subsequent withdrawal from Iraq, Iran's ability to project power into Iraq has only grown.

Here are various ways in which Iran is constantly expanding its power in Iraq:

The formation of Shiite militias

Following ISIS's blitz throughout Iraq and the group's march on Baghdad, Iranian-funded Shiite militias were re-mobilized. The most powerful of them was the Badr Organization, an Iranian-backed political and military organization that has carried out revenge attacks against Sunnis throughout Iraq.

That became an issue for the US since such sectarian militias, generally loyal to Iran, killed and maimed hundreds of American soldiers during the Iraq war.

"It's a little hard for us to be allied on the battlefield with groups of individuals who are unrepentantly covered in American blood," Ryan Crocker, career diplomat served as U.S. ambassador to Iraq from 2007 to 2009, told US News.

More recently, the so-called Special Groups have played a pivotal role in halting ISIS after the Iraqi Army disintegrated.

"Iran and its Iraqi proxies have been carving out a zone of influence in eastern Iraq for well over a decade," Michael Knights, a fellow at the Washington Institute, writes. "And this zone, as [U.S. Chairman of the Joint Chiefs of Staff General Martin Dempsey] noted, is expanding.

The introduction of heavy weapons and warplanes

To assist in the siege of Tikrit and further military operations against ISIS, Iran has moved advanced rockets and artillery systems into Iraq, reports the New York Times.

These systems have introduced a new level of sophistication into the Iraqi warzone and could further inflame sectarian tensions as the artillery is often imprecise and has the potential to cause collateral damage.

"The Fajr-5 rocket and Fateh-110 missile launching systems are typically carried on a specially designed truck and are formidable additions to the Iraqi arsenal," notes the Times. "Fajr-5 rockets, which are named after the Persian word for dawn, have a range of about 45 miles. Each is 20 feet long and weighs more than 2,000 pounds. The Fajr-5 warhead alone weighs 375 pounds. ... The Fateh-110 missile is even more capable than the Fajr-5."

In November 2014, Iranian pilots bombed ISIS positions in the Iraqi province of Diyala. Diyala was is a religiously mixed Iraqi province that abuts Iran.

The presence of Iranian planes conducting airstrikes at the same time as US military operations showed at least a deconfliction between the two countries' militaries. (The same thing is happening in Syria.)

Ahmad Al-Rubaye/AFP/Getty Images

Iraqi Shiite militia fighters raise up their weapons as they celebrate pushing back ISIS militants on Sept. 3, 2014, on the road between Amerli and Tikrit, in Iraq.

The presence of Qassem Suleimani

Iran's military mastermind, Qassem Suleimani, has played pivotal roles in the deployment of Iranian assets against ISIS in Iraq. Suleimani was present during the successful siege of Amerli in August and he is currently on the front lines of the battle against ISIS in Tikrit.

Suleimani is the head of Iran's Revolutionary Guard Corps' Quds Force, putting him in charge of directing Iranian proxies throughout the Middle East. His constant presence in various front line battles serves to underscore the propaganda of an ascendant Iran with its forces battling for control throughout the region.

The battle for Tikrit

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Qassem Suleimani drinking tea at Tikrit.

Tikrit is currently under siege by a coalition of Iranian-backed Shiite militias and Iraqi army forces. The offensive is being overseen by Suleimani. Should the forces liberate Tikrit from ISIS, Iran will have scored a significant propaganda win.

The seizure will both place Iranian-backed forces on the road to Mosul as well as humiliate Sunnis by having Iran take control of Saddam Hussein's hometown.

Furthermore, the US has to sit back and watch.

"There's just no way that the US military can actively support an offensive led by Suleimani," Christopher Harmer, a former aviator in the United States Navy in the Persian Gulf who is now an analyst with the Institute for the Study of War, told Helene Cooper of the New York Times. "He's a more stately version of Osama bin Laden."

'Export the revolution'

Iran's ambition's go far beyond Iraq and is taking them increasingly closer to the borders of its regional adversaries.

Last month, Suleimani gloated: "We are witnessing the export of the Islamic Revolution throughout the region. From Bahrain and Iraq to Syria, Yemen and North Africa."

Tony Badran, a research fellow at the Foundation for Defense of Democracies, explains what Iran's military mastermind means by this: "When he talks about exporting the Islamic Revolution, Suleimani is referring to a very specific template. It's the template that the Khomeinist revolutionaries first set up in Lebanon 36 years ago by cloning the various instruments that were burgeoning in Iran as the Islamic revolutionary regime consolidated its power.

"As a result, Hezbollah remains the most comprehensive and developed export of the Iranian model. ... Now the Islamic revolutionary model is being reproduced in Iraq, Syria, and Yemen as well, by setting up those same structures."

That why Ali Khedery, who served as a special assistant to five US ambassadors and a senior adviser to three heads of US Central Command between 2003 and 2009, told the New York Times in December that Suleimani is "the leader of Lebanon, Syria, Iraq and Yemen," adding that "Iraq is not sovereign. It is led by Suleimani, and his boss, [Iranian Supreme Leader] Grand Ayatollah Ali Khamenei."