OTTAWA - Stephen Harper's willingness to send combat advisers to Iraq ahead of making a firm commitment of troops to NATO's newly bulked-up rapid reaction force has as much to do with budget as it does with his government's searing experience in Afghanistan.

A joint committee of MPs and senators will have the opportunity Tuesday to grill both Foreign Affairs Minister John Baird and Defence Minister Rob Nicholson about the impending dispatch of dozens of special forces troops to advise Iraqi and Kurdish forces battling the Islamic State of Iraq and the Levant (ISIL).

Much to the alarm of the NDP and to a lesser extent the Liberals, Harper did not rule out making further commitments to battle extremists in the region following last week's NATO summit in Wales.

Eric Morse, a former diplomat, said the prime minister is throwing his lot towards the threat the Americans see as the most immediate, something that may take some of the sting out of his testy relationship with Washington.

"Sending 100 special forces (soldiers), he can hold the line on that and he's showing the Americans he's willing to play ball with them in an area that's of interest to them," Morse said.

The Obama administration is expected to lay out its strategy for dealing with ISIL on Wednesday. The Canadian government may also be under pressure to take on ISIL because of the threat of returning jihadist fighters, Morse added.

Steve Saideman, chair of the Paterson school of International Affairs at Ottawa's Carleton University, said it also likely represents a mistrust of NATO in light of the alliance's lethargic response to Canadian pleas for reinforcements in Kandahar.

Harper's pleas for help in battling a resurgent Taliban early in Canada's combat mission in Afghanistan fell largely on deaf ears. In the end, the U.S. provided a battalion of 600 troops to help stem the tide.

"The choice of ISIL versus the Baltics makes sense from two standpoints. One, the hostility towards NATO and the desire to do things in a bilateral and trilateral way," said Saideman.

"The second, this government has been much more willing to fund and support special operations forces than the (regular) army, which has been quite vocal about being hollowed out by budget cuts."

Further, special forces often operate secretly without drawing media attention, which Saideman said would be a plus to the government.

Canada's contribution to reassuring eastern Europe involves fighter jets, a frigate and a company of soldiers for exercises, all of which are quick, low-cost demonstrations of solidarity.

But Morse said Canada increasingly strengthened its ties with the U.S. military and treated commitments with established multilateral groups such as NATO and the UN with reservation.

The Liberals say ISIL must be confronted, but they want to know to what extent Canada will be involved and will support a non-combat mission. The NDP, meantime, are extremely wary of the Iraq deployment, even though it is slated to last only 30 days, and fear so-called "mission creep."

But the risk of the mission growing larger isn't great, said Morse, since budget cuts have hollowed out the army's capacity to mount an expeditionary operation of the kind they conducted in Afghanistan.

"He doesn't have the troops to do very much," Morse said. "I don't think we could get an expeditionary force, like the size we sent to Kandahar, together now."

A series of internal National Defence documents, obtained by The Canadian Press under the Access to Information Act, show the army could mount a battle group-sized deployment to the world's trouble spots, but would have a tough time sustaining the operation.

The air force, with its Norad duties and jets already deployed in the Baltic, would be stretched to contribute any more fighters to missions in Iraq. It might be able to deploy additional transport planes and helicopters for relief missions, should the need arise.