It was bound to happen to Musharraf, someday

Every dictator in the world has faced it. An ultimate fall to doom is their fate. This fate has now caught up with the Pakistan President, too. His final expected straw of support was from the Army. Parvez Musharraf had planned for it in advance.
The Pakistani army chief Ashfaq Parvez Kayani owed his powerful post to Musharraf. He could have been the only person to save the embattled president's job. Unfortunately for Musharraf, Kayani has opted to stay out of the fight.
The implicit refusal of the Army to play the game Musharraf’s way has left the President limited options. He has now to choose between resigning and facing impeachment proceedings. A resignation seals his face where as facing impeachment, apparently, means a near certain chance of losing.

Opportunistic relations
Politics is infamous for never having permanent friends. It has only permanent interests. The interests of the army chief now lie elsewhere. So, Kayani wants the confrontation between Musharraf, 65, and parliament's ruling coalition settled without any public upheaval. His reticence means the armed forces that probably won't support any invocation of his authority to dismiss parliament because that might incite street protests.
Kayani also is unlikely to let Musharraf's detractors put him on trial once he leaves office for leading the coup because ‘that would draw the military into politics.' The army chief seldom speaks publicly and declined to be interviewed. Insiders say, he has displayed his independence only since last year, when as intelligence chief he refused to back Musharraf's firing of Pakistan's chief justice.
The dismissal of Chief Justice Choudhary had sparked nation-wide protests and many more Pakistanis turned against the president.

The silent patron
The USA has been acting as the most reliable ally for the President. There has been a deafening silence from that quarter too. Not only that many senior officers from the US administration also have been visiting Kayani of late.
Even before February elections that put anti-Musharraf lawmakers in control of Parliament, Kayani ordered officers to cut off contact with politicians. Pakistan though has a history of the military meddling in past national politics.
Last heard, Musharraf was negotiating a safer way out for himself.