President Obama's Thursday announcement to send 300 military advisers to Iraq to try to help the country's security forces beat back a rapidly advancing al Qaeda-inspired insurgency, has prompted more questions than it answered.

Here are five answers to some of the basics:

Who will serve as the military advisers?

U.S. Special Operations forces – likely Army Green Berets, Army Rangers and Navy SEALs – separated in teams of about a dozen.

What will they do?

They will be sent in to advise the Iraqi military and collect intelligence to assist in attacks against the extremist group the Islamic State of Iraq and Syria, or ISIS, such as their location, their numbers and weaponry.

The information can help the Iraqi army target the fighters and could also provide key intelligence needed if Obama decides to pursue airstrikes against ISIS.

They will be embedded "mostly at the higher headquarters level within the [Iraqi military], perhaps at the brigade level" in joint Iraqi-U.S. Operations centers in Baghdad and northern Iraq, a senior administration official told reporters Thursday.

Will it help?

While many members of Congress dismissed the step as too little, too late, including Sen. James Inhofe, R-Okla., the ranking member of the Senate Armed Services Committee, there is a successful precedent.

Small teams of U.S. Special Forces and CIA paramilitary officers were sent to Afghanistan in the the fall of 2001 to work with Afghan fighters to target the Taliban and coordinate airstrikes against them.

The assistance and the strikes were credited with boosting the Afghan Northern Alliance's ability to push back the Taliban and wrest the Afghan capital, Kabul, from them.

Will they have immunity from prosecutions if they defend themselves in an attack?

The short answer is no, but an administration official said Thursday "we are confident that these additional forces will have the protections and authorities to be there, particularly as Iraq has requested them."

When asked if he regretted not keeping a residual U.S. military force in Iraq after 2011, Obama squarely pinned the blame squarely on Iraqi Prime Minister Nouri al-Maliki for refusing to sign a Status of Forces agreement that would grant remaining troops immunity from possible crimes if they were forced to defend themselves.

"Keep in mind that wasn't a decision made by me," he said. "... The Iraqi government and Prime Minister Maliki declined to provide us that immunity."

Republicans say the Obama administration could and should have pushed harder for the agreement.

Given the small size of the forces and their limited mission, the administration official said a Status of Forces agreement with al-Maliki would not be necessary.

How will Congress pay for it?

Obama, in his Thursday statement, said he would work closely with Congress to fund the new mission in Iraq from a new Counterterrorism Partnership Fund he proposed during his speech at West Point in May.

Rep. Buck McKeon, R-Calif., who chairs the House Armed Services Committee, issued a statement later Thursday saying Obama had yet to send a proposal for the fund to Congress, even though the law requires him to submit all budget request to Congress in February.

"It’s true that the events in Iraq are unraveling rapidly, but if this fund has any merit, the president’s indecisiveness to date now means he has missed the primary opportunities for the House to consider this proposal," he said.

The Defense Authorization bill, which approves all defense funding, passed the House last month, he said, and lawmakers were voting on portions of the defense spending bill Thursday night.

Rep. Adam Smith, D-Wash., the ranking member of the Armed Services Committee, said he didn't know specifically why Obama hadn't sent the request to Congress and how he planned to pay for the new mission in Iraq, noting that it could come from funds devoted to the military's special operations.

More likely, the money will come from the so-called war budget, outlays from the Overseas Contingency Operations, a supplement to Pentagon spending used to fund the remaining troops in Afghanistan.

Obama has yet to tell Congress how much he wants for the fund for the coming fiscal year, even though it also was due in February. The Pentagon established a placeholder budget of $79 billion, and a House GOP aide said the administration keeps saying it will send up its actual request soon.