The professor believes the U.S. will choose the first option and withdraw as scheduled, because they justify their pullout as saying that the level of violence has dropped dramatically compared with 2006 or 2007 and Iraqi security forces are capable to take over the security file in Iraq.

"I also want to say that if the U.S. delays the pullout it will encourage the militias to carry out more attacks. As a matter of fact, the delay would be a reward to these acts of terror and it will encourage those parties which hope to sabotage the political process," he said.

"I think the best way is to go ahead with the pullout plan, moreover, it is a political suicide for both the Iraqi leaders and the U.S. administration to keep troops in Iraq for an additional day," said the professor.

However, due to the current political deadlock as Iraqi politicians still failed to form a new government near five months after the elections, some people also accuse the United States of trying to leave the war-torn country unstable just for their own interests.

Challenges for Iraq after U.S. pullout

Professor Shiekh held similar opinion, "as for the Iraqi government's ability to control the political and security situations after the U.S. pullout, I am skeptical about that, as the pullout by the end of 2011 would give a great opportunity for the Iranian influence to prevail which may provoke fierce conflict between the followers of Iran-backed Shiite Muslims and the followers of Arab-backed Sunni Muslims in Iraq," Shiekh said.

"It is known that some Shiite parties were formed and trained in Iran. Those parties are leading powers in the post-Saddam Iraq and they will see the U.S. withdrawal as a great victory for them and for the Iranian influence in Iraq," he added.

"Another challenge for the Iraqi government after the U.S. pullout is the struggle between the Arabs and Kurds about the disputed areas outside the Kurdish semi-autonomous region, the oil law and the distribution between the central government and the Kurdish region," said Shiekh.

Troops from the Iraqi government and the Kurdish government have been occasionally clashing with each other in the past years. The U.S. forces sometimes had to mediate between the two sides and that has raised fears on how far the tensions would develop in the future after the U.S. withdrawal.