When asked, “Will the mission [in Libya] be over by the end of the year?” last week on ABCâÄôs “This Week,” Secretary of Defense Robert Gates said, “I donâÄôt think anybody knows the answer to that.”

NATO, an international organization dominated politically and militarily by the U.S., assumed the command of Libya on March 30. However, despite the handoff, the U.S. will still have a role in Libya.

While there are a wide variety of factors that will determine just how long NATO will be in Libya, such as the strength of opposition and our strategy, the main factor is our goal: Will we seek to establish a new democracy in Libya or simply to depose Moammar Gadhafi?

Either way will not be short or easy, if recent history is an accurate guide.

Six weeks after the initial invasion of Iraq, President George W. Bush gave a speech that said the conventional Iraqi forces had been defeated. Despite this success, we still had a long war ahead of us.

A series of provisional governments and governing councils were phased in and out of operation starting in July 2004, to give Iraqis control of their own government.

In 2006, a republic was established, with the U.S. government working diligently to help protect it.

As of Jan. 1, 2011, there were 47,000 U.S. troops in Iraq, and while violence is not uncommon in Iraq, it has decreased considerably.

In Afghanistan, on the other hand, the U.S. has taken a much different approach. We didnâÄôt escalate the conflict to the level seen in Iraq and as a result, progress has come at a much slower rate. We are still nowhere near withdrawing, and Osama Bin Laden still hasnâÄôt been found.

In other words, if we hope to see success in Libya, we should be prepared to be involved for a minimum of eight years âÄî which is how long we have been in Iraq âÄî and prepare to see the deployment of troops into Libya.

The approach we take in Libya can model a full-scale intervention, like in Iraq, or we could use less intervention, like we did in the less successful Afghanistan campaign.

We could simply aid the rebels and then stop being involved. This will result in a relatively quick mission.

The result, however, could be another dictator with stronger anti-Western views and even less regard for human rights coming to power and turning Libya into a national security threat. The Iranian revolution of 1979, where Ayatollah Khomeini came to power, provides a perfect example of this.

The main point is that there will be a massive struggle for power if Gadhafi is deposed. With the U.S. intelligence community suggesting that al-Qaida is aiding the rebels, the result in Libya could be devastating to American security in the long run.

The course of action taken in Libya puts President Barack Obama in a precarious position: While strong military action in Libya is the best solution to protect long-term U.S. interests, it will cost him support in his political base and not help him garner political support outside it.

ObamaâÄôs opposition to the Iraq War was a major reason he won the 2008 Democratic presidential nomination. Obama opposed the war because, while Saddam Hussein was a horrible dictator, he wasnâÄôt a threat to the U.S.

That line of thinking leaves any objective observer puzzled as to how he justified military action against Libya.

Mounting a military intervention to help Libyan rebels establish a new government will damage ObamaâÄôs reputation and support among his left-leaning supporters because they will see him as a re-incarnate of Bush.

Meanwhile, those who supported the Iraq War still wonâÄôt support Obama because they tend to strongly oppose his domestic policies.

The political reality of needing to cater to your base before an election leaves Obama with one choice, which is to use the least amount of intervention possible. In the short term this will garner him support, but in the long term could harm U.S. interests.

Suppose the NATO airstrikes over the next month or two result in rebel forces defeating Gadhafi and the U.S. then ends all involvement in the war. There will be a power struggle to establish leadership and a government over the following months. Once itâÄôs clear who the new Libyan leader is, it will take more time for his true allegiances and views to become known.

Using the lowest level of intervention is best for Obama politically, because by the time this course of events takes place, the 2012 election will likely be over and Obama will be supported for the initial success of the mission but not judged on the future national security risks if a more extreme dictator rises to power.

As we have seen with Iraq, forming a new nation is a difficult task, and even under the best case scenario, NATO involvement will not be brief if we seek a favorable outcome.

Ensuring that a stable, non-extreme government is created in Libya means that U.S. intervention in Libya will not be for a few weeks, or a few months, it will likely be many years.

Obama is in a difficult position. He will either lose support from his political base or heâÄôll be risking the long-term security of the U.S.

Nobody may know exactly how long we will be in Libya, but one thing is for sure âÄî if a responsible course of action is taken, it will take a while and come at a great cost.

Josh Villa welcomes comments at [email protected].