By Peter Apps, Political Risk Correspondent
LONDON (Reuters) - Foreign powers attacking Libya may hope air and missile strikes alone will topple Muammar Gaddafi and perhaps usher in democracy -- but recent history suggests they could be in for a long and complex engagement.
Air strikes aimed at halting ethnic violence had only limited effect in achieving their goals in Bosnia and Kosovo until backed with the threat of effective ground action or at least the deployment of well-armed peacekeepers.
In Afghanistan, an air campaign and special forces support was enough to oust the Taliban from power after the September 11, 2001, attacks -- but that war is far from over a decade on with thousands of NATO troops battling an ongoing insurgency.
In Iraq, more than a decade of sanctions, a no-fly zone and repeated bouts of air strikes that followed the end of the 1991 war helped Kurdish regions remain largely free from Saddam Hussein but otherwise allowed him to remain in power.
A change in western policy and overwhelming military force swiftly ended his rule in 2003, but that proved the beginning of a bloody civil war and protracted U.S.-led military intervention is only just drawing to a close.
The speed with which Britain, the United States and France have found themselves effectively at war in Libya at a time when much attention was focused on Japan's earthquake has meant there was little of the public debate that preceded the 2003 Iraq war.
"There's obviously the issue of timing -- that leaving things any longer would have allowed Gaddafi to produce a bloodbath," said Anthony Skinner, associate director of political risk consultancy Maplecroft.
"But it's still far from a foregone conclusion that this will work. Gaddafi obviously has a vested interest in dragging things out in the hope that he will survive. In the long run, stopping him might require the deployment of ground troops and there seems very little appetite for that and resources are very thin."
The United Nations resolution that ushered in action to protect civilians specifically ruled out a foreign occupation but endorsed "all necessary measures" to protect civilians.
Perhaps deliberately, that leaves many options including limited ground intervention in support of rebels already recognized by France as the legitimate government of Libya.
The question, analysts say, is how much political will is really there -- and what they want to achieve with it.
"The long-term goal, unspoken but well understood, is regime change," wrote George Friedman, head of political risk consultancy Stratfor.
"It should be remembered that in Iraq and Afghanistan ... regime change was merely the opening act. It is possible that the coalition partners haven't decided on the strategy yet, or may not be in agreement."
France and Britain have both occasionally intervened in African civil wars in the past decade -- such as in Sierra Leone in 2001 -- but on the side of governments.
Backing rebels against a strong central authority is a different matter -- likely requiring more outside intervention should Gaddafi's rule crumble or collapse.
"Once it looks possible to force a political process, the international community will need to back a diplomatic engagement," said senior policy fellow Daniel Korski at the European Council on Foreign Relations, a veteran of reconstruction efforts in Iraq, Afghanistan and the former Yugoslavia and strong supporter of intervention in Libya.
He said the European Union and NATO might have to be involved perhaps with the Arab League or African Union in what he called a "light-touch monitoring mission."
With French jets targeting Libyan armored vehicles on the outskirts of Benghazi on Saturday, military action has already gone well beyond the "no-fly zone" initially suggested by Britain and France and endorsed by the Arab League.
"AIR POWER HAS LIMITATIONS"
Even with air strikes, most experts believe the rebels will need outside help to improve their currently near-nonexistent command and control capabilities.
The bottom line, some strategists say, is that there are some things only ground forces can do. Once Gaddafi's forces are mixed amongst civilian areas, there may be little air strikes can achieve without considerable "collateral damage."
"Air power has its limitations," said Henry Wilkinson, lead analyst at security consultancy Janusian. "It will not inflict a decisive blow, nor prevent attacks on civilians in all cases. Only ground forces can take territory, provide local security and impose their political will upon an enemy."
Analysts point to many unknowns. Will intervention in Libya give new confidence to protesters in other autocratic Middle Eastern states including oil producers -- and how might the West respond? Could civilian casualties turn local, regional and domestic Western opinion against the campaign and play into the hands of Islamist militants?
"The early days will go extremely well but will not define whether or not the war is successful," wrote Stratfor's Friedman. "The test will come if a war designed to stop human suffering begins to inflict human suffering. That is when the difficult political decisions have to be made."
(Editing by Sonya Hepinstall)