FACTBOX-No easy options in Pakistan post-poll scenarios

ISLAMABAD (Reuters) - Nuclear-armed Pakistan is due to hold an election on February 18 that has its neighbours and the West shuddering over what might happen next in a country at risk of being destabilized by al Qaeda.

Here are some of the possible election scenarios, based on Pakistani political analysts and foreign diplomats assessments:

THE BACKDROP

-- Although it is not a presidential vote, U.S. ally President Pervez Musharraf's position could be in danger if the election produces a hostile parliament that could seek his impeachment.

-- Musharraf, who came to power as army chief in a 1999 coup, secured a second term as president by imposing emergency rule in November for a few weeks in order to purge the Supreme Court of judges who stood in his way.

-- Opinion polls show most Pakistanis do not believe Musharraf should lead them any longer and, having quit the army to become a civilian president, he is regarded as weaker than ever before.

-- The country is still reeling from the shock of opposition leader Benazir Bhutto's assassination on December 27, and campaigning has been low key due to security fears after a wave of suicide attacks and violence across the northwest.

-- The West is concerned that a Pakistan caught in political flux could lose focus in the war on terrorism, though the United States appears confident in new army chief General Ashfaq Kayani.

MUSHARRAF'S HOLD ON POWER

-- If Musharraf is lucky there will be no clear winner, and no one will be strong enough to unseat him.

-- The one combination that Musharraf dreads would be an alliance between Bhutto's Pakistan People's Party and the party led by the Nawaz Sharif, the prime minister he ousted in 1999.

-- The other danger for Musharraf during this time is violence. Should PPP and Sharif's party, variously known as PML-N or Nawaz League, say they were cheated by vote-rigging they could call for street protests. It would be a recipe for turmoil.

If the army had to restore order, generals might decide that Musharraf was too unpopular and advise him to step aside.

-- Musharraf's political support comes from the Pakistan Muslim League, the party he split when he ousted Sharif. The wing that hooked up with Musharraf is known as PML-Q or Q League.

Almost everyone, barring Musharraf, agrees that unless polls are rigged the Q League will lose many of the 130 seats it controlled in the last National Assembly.

Pakistan hasn't had an election regarded as free and fair since 1970.