Not long ago, Mohammed Dahlan was a rising political star, a Gaza security chief and darling of the West. He advised the Palestinian president and was even considered a possible successor.

But after a falling out with President Mahmoud Abbas, Dahlan has been essentially banished from the political scene. The campaign against him casts an unflattering light on the Palestinian president's low tolerance for dissent as peace talks with Israel falter.

Dahlan's rapid downfall, like attacks on other critics of the president, also reveals the extent to which the West — despite its preaching of democracy — seems inclined to look the other way as Abbas uses largely unchecked powers to dress down political rivals.

That bargain is a result of the belief by some that Abbas is indispensable to pursuing peace with Israel and maintaining the current calm, though the U.S.-backed peace effort has stalled.

Palestinian analyst Hani al-Masri said Abbas' moves against Dahlan are in a way the result of frustration with the lack of progress toward a Palestinian state, which leaves leaders like Abbas feeling vulnerable.

"There is a trend in the Palestinian Authority of being less tolerant due to the failure of the peace process," he said.

Dahlan began losing standing in 2007, when the Islamic militant group Hamas, with amazing speed, routed forces under his command to take over the Gaza Strip. Persistent corruption allegations have also sapped his support among ordinary Palestinians. Still, he was allowed to relocate to the West Bank where he remained a close adviser to Abbas.

But two months ago, Abbas heard his former protege had criticized him in meetings with party activists, officials close to Abbas said. According to the officials, who spoke on condition of anonymity because of the sensitivity of the issue, Dahlan also called Abbas "weak" in meetings with Palestinian diplomats abroad.

Things fell apart quickly for Dahlan after that.

In November, Fatah set up a committee to investigate charges he was trying to form an anti-Abbas bloc inside the party. It also stripped Dahlan of his personal security guards — a huge slap for the man who once commanded thousands of Abbas' security forces in Gaza.

Last month, Fatah replaced Dahlan as the party's spokesman and barred him from participating in meetings of its highest body until the committee finishes its investigation. The interior minister also banned a TV station that Dahlan co-owned — "Palestine Tomorrow" — which was to begin broadcasting this month.

Speaking to The Associated Press in his Ramallah office Monday, Dahlan denied all accusations, calling them "fictional accounts and fairy tales" stirred up by "hateful people" seeking to damage the ruling Fatah movement. He said he fully supports Abbas and said he expects the issue to be over soon.

"This entire show is bogus and its goal is to stab the movement in the back," he said, calling the moves against him "shameful, illegal and immoral."

Abbas himself has not addressed the issue in public.

But the case appears personal, brought on by the Palestinian leader's intolerance for criticism, said political analyst Mouin Rabbani.

"Abbas is extremely sensitive, exceptionally thin-skinned and has an exceptionally high opinion of himself, so the mere act of making personal criticism of him puts you beyond the pale," said Rabbani, who is a senior fellow at the Institute for Palestine Studies.

Dahlan, known as a shrewd political operator, has made other enemies in the past, making it easier for Abbas to target him, Rabbani said.

Fatah, which has dominated Palestinian politics for nearly half a century, has long been characterized by political intrigue and shifting alliances.

And while Abbas is not nearly as popular or authoritative as his predecessor Yasser Arafat, he has considerable support worldwide because he is seen as running a much cleaner government and is more convincingly committed to nonviolence.

His government has won praise for its campaign to bolster its case for independence by strengthening domestic institutions, focusing on issues like internal security and legal reform.

In this context — especially after the West's widespread frustration with efforts to promote democracy in the Middle East — true political reform is scarcely discussed.

After Hamas took over Gaza, Abbas' term was extended under an emergency order, but it ended last year. He unapologetically stayed on, his government later canceled local elections, and there is no talk of when new elections will be held for any office.

In a reflection of the complex wider considerations at play, Abbas has cracked down most publicly on those who — unlike Dahlan — criticize his decision to negotiate with Israel.

In August, dozens of men believed to be plainclothes security officers broke up a gathering of activists who opposed his decision to enter peace talks, which began the following month and have since stalled. Uniformed officers also waited outside to question the activists as they left.

Later, a when a smaller Palestinian faction stopped attending meetings of the Palestine Liberation Organization to protest Abbas' decision to enter talks, he cut off the group's monthly stipend.

Independent human rights groups have also accused his forces of arbitrarily arresting Hamas members, some of whom complain of sporadic torture.

Now it is Dahlan's supporters being targeted.

In November, Palestinian security detained about a dozen former militants loyal to Dahlan in the northern West Bank, a Palestinian security official said. They were released 10 days later, the official said.

On Friday, Palestinian security detained Dahlan's office manager, Moataz Khedeir, and have held him incommunicado since, family members said, speaking on condition of anonymity for fear of retribution.

Khedeir's job was to send news releases and text messages to journalists about Dahlan's activities.