Members of Congress grilled the head of U.S. Central Command Thursday over recent moves by Iran to control the conflicts in Iraq and Yemen.
Shiite Houthi rebels have attacked several cities in Yemen, which has resulted in the evacuation of U.S. Special Forces and other troops and prompted Saudi Arabia and several of its allies to launch large-scale military operations into the strife-torn country.
The deteriorating situation had lawmakers for the Senate Armed Services Committee asking tough questions about the U.S. strategy in the Middle East and its inability to keep Iran from asserting influence over the region.
Once hailed by President Barack Obama as a model for fighting extremism, the U.S. counterterrorism strategy in Yemen has all but collapsed as the country descends into chaos.
The new tension puts the United States, a traditional ally of Saudi Arabia, in a precarious situation with Tehran as it tries to negotiate a nuclear deal before the end of this month.
Sen. Kelly Ayotte, R-N.H., questioned General Lloyd J. Austin, commander of U.S. Central Command, over Iran's interference with U.S. counter-terrorism operations in Yemen while it has been negotiating with the State Department over the controversial nuclear agreement for the past year.
"During that period, what has Iran been doing in Yemen? Is it not a fact that Iran's influence and support of the Houthis which is in part prompting the Saudis and others to engage in this?" Ayotte asked.
Iran wants to dominate the region and supports Shiite populations as a way of increasing its influence in various countries, Austin said, describing how this works as a destabilizing mechanism.
Ayotte quickly countered this assessment.
"Let me just be clear when we are talking support ... we are talking about money and arms, aren't we? We aren't just talking about ‘boy we support you because you are Shia?'" Ayotte said.
"Yes senator, we are talking about material support as well," Austin conceded.
Shiite rebels seized Yemen's third largest city of Taiz and its airport on Sunday, as thousands took to the streets in protest.
The seizure comes two days after a group of about 100 U.S. military forces, including Special Forces troops, evacuated an air base after al-Qaida seized a nearby city, Yemeni military and security officials said Saturday.
SACS Chairman Sen. John McCain, R-Ariz., made a point of asking Austin when his counterparts in the Saudi military notified him of the country's plans to launch the air campaign against Yemen rebels, codenamed Operation Decisive Storm.
Austin said he was notified shortly before the operation began.
"Right before they took action -- that's very interesting," McCain said.
Saudi Arabia deployed some 100 fighter jets, 150,000 soldiers and other navy units, Saudi-owned Al-Arabiya TV reported. Also involved in the air operation were aircraft from the United Arab Emirates, Bahrain, Qattar, Kuwait, Jordan, Morocco, Sudan and Egypt, though it was not clear which carried out actual strikes.
Three Egyptian military and security officials told The Associated Press that a coalition of countries led by Egypt and Saudi Arabia will conduct a ground invasion into Yemen once the airstrikes have sufficiently diminished the Houthis and other forces.
McCain said he was also concerned that U.S. airstrikes are supporting Iranian forces in Iraq in the fight against militants of the Islamic State of Iraq and Syria.
"Iran is not our ally, yet we learned just yesterday that the U.S. is providing air support in Tikrit, which media is reporting is being fought by 20,000 to 30,000 Iran-backed Shia militia fighters and only 3,000 to 4,000 Iraqi security forces."
Austin corrected McCain, explaining that U.S. airstrikes are only supporting about 4,000 Iraqi forces in Tikrit and that Shia militia units have pulled out of the area.
"So why do we see pictures of Soleimani orchestrating and leading this effort?" McCain asked, referring to Qassem Soleimani, an Iranian general helping Shia militias fight ISIS in Iraq.
Austin told McCain: "Those pictures were from before, and as you know, that effort that Soleimani and the Iranians were sponsoring, it stalled."
At a Pentagon briefing, Army Col. Steve Warren, a Defense Department spokesman, said that not every Shiite militia group has pulled back from the vicinity of Tikrit because "not every Shiite militia unit is Iranian- backed."
"Certainly the [Popular Mobilization Committee] Shiite militia is paid by the Iraqi government," Warren said. "They have a presence inside [the combined operations center]. They have a seat at the table. They are recognized by both the Iraqis and by the coalition as a legitimate piece of the Iraqi security force establishment."
Warren said that Iraqi Prime Minister Haider al-Abadi formally asked for U.S. air support on Wednesday, and bombing in and around Tikrit began the same day, with a total of 17 airstrikes reported.
However, Warren said that discussions on U.S. air support and the withdrawal of the Iranians and the Shiite militias had been underway for several days with the Iraqis. U.S. surveillance flights over Tikrit began on March 21.
Warren said that several hundred well-entrenched ISIS fighters were believed to be in Tikrit with the Iraqi.
But much to the chagrin of many senators, Austin said that the most immediate threat still facing the U.S. in the region is ISIS.
"We are having significant effects on the enemy," Austin said. "We continue to [attack] its forces in Iraq and Syria, we have attacked its command and control capabilities, we have destroyed its training sights and facilities along with hundreds of its vehicles tanks and heavy weapon systems. ... Make no mistake [ISIS] is losing this fight."
-- Military.com's Richard Sisk and the Associated Press contributed to this report.
-- Matthew Cox can be reached at firstname.lastname@example.org