Mehdi Army fighters loyal to Shi’ite cleric Moqtada al-Sadr march during a parade in Najaf, Iraq, on June 21. (Alaa Al-Marjani/Reuters)

When the United States pulled all but a handful of its remaining troops from Iraq in late 2011, it was in large part because Baghdad and Washington could not reach an agreement that would have granted U.S. troops legal immunity from Iraqi prosecution. Not having such an agreement left open the possibility that Americans could have been tried and imprisoned by Iraqi authorities for the messy results of a firefight, rather than facing the U.S. military’s Uniform Code of Justice.

Times have changed. With no end sight to the spiraling Iraqi security situation, President Obama signaled Thursday that he would send up to 300 U.S. military advisers — likely elite Green Berets — to assist and advise floundering Iraqi security forces. That raised the question whether legal immunity was coming with it, since it was widely believed it would require approval from the Iraqi parliament.

Pentagon spokesman Rear Adm. John Kirby indicated Monday that isn’t the case. The United States has now received “acceptable assurances” on the legal protections the new military advisers there will have, and it came through a diplomatic note, rather than parliamentary vote, he said.

“Specifically, Iraq has committed itself to providing protections for our personnel equivalent to those provided to personnel who were in country before the crisis,” Kirby said. “We believe these protections are adequate to the short-term assessment and advisory mission our troops will be performing in Iraq. With this agreement, we will be able to start establishing the first few assessment teams.”

U.S. officials have not yet clarified why a parliamentary vote is not required anymore. Meanwhile, militants with the Islamic State of Iraq and Syria, an al-Qaeda offshoot, have seized control of three more towns and Iraq’s main border crossing with Jordan, tightening their grip on Anbar province. The insurgents — and Sunni tribes that have revolted against Prime Minister Nouri al-Maliki — now have control of hundreds of miles of territory spanning the Iraqi-Syrian border, in addition to control over swathes of land in Iraq’s north.