By Chris Allbritton
ISLAMABAD (Reuters) - Pakistan's disparate Islamist political parties are uniting behind their hatred of the United States, emboldened by a weak government that looks increasingly reluctant to stand up to extremism and a society where radicalism is widely tolerated.
The prospect of these parties gaining strength in this nuclear-armed nation is a nightmare for its ally the United States and neighbors including India and Afghanistan, which are already fighting Islamist insurgents based in Pakistan.
But while there is little chance Islamist parties will be able to take power outright, they are becoming more prominent as anti-Americanism grows among ordinary Pakistanis, many of whom also reject attempts to soften a blasphemy law that has claimed the lives of two senior officials this year alone.
"The government is struggling to respond to populist forces at precisely the moment when it aims to improve its position to secure a full term and better position itself for the 2013 elections," wrote analyst Maria Kuusisto of consultancy Eurasia Group in a research note.
Elections could, however, come even earlier if the unpopular ruling coalition stumbles over a range of issues.
These include rising fuel prices and other economic reforms mandated by the International Monetary Fund but reviled by the people and the government's handling of the case of U.S. CIA contractor Raymond Davis who is on trial for murder.
Islamists parties, who traditionally have done poorly at the polls, stand a better chance if elections are held nowadays, analysts said.
And if they increase their numbers in parliament, they could force a new government to the right, shake the alliance with the United States, including ending cooperation against the war in Afghanistan, and push the government into concessions with Pakistani Taliban militants.
"There are strong chances for the revival of the Muttahida Majlis-e-Amil (MMA)," said Islamist politician Abdul Wahab Madni on the reformation of a major Islamist bloc from the early 2000s. "And this time, other religious groups would also join."
Most of the parties support Afghanistan's Taliban and they all want to impose strict sharia law.
Farid Paracha, a senior leader in the Jamaat-e-Islami (JI), one of the country's main religious parties which is involved in the new bloc, said the alliance would win 60 percent of National Assembly seats if an election were held today.
Analysts say his assessment is too optimistic, but gains are likely.
"They may get more seats than they got in 2008 elections, but they are not going to win all over," said Hasan Askari Rizvi, an independent political analyst. "What they're doing is trying to focus the whole thing on one or two issues."
NEW BLOC, SAME AGENDA
While they are able to draw big crowds to protests, the parties have never mounted much of an electoral challenge.
Their best showing was in a 2002 election, when anger with the United States was at fever pitch after the U.S.-led invasion of Afghanistan, and the MMA won 59 of 342 assembly seats.
MMA members later drifted apart and fared poorly in the last election in 2008. They now appear more determined to unite.
The new bloc has yet to be officially launched but includes at least 18 parties representing most of Pakistan's sects and factions, including Sunnis, Shi'ites, Deobandis and Barelvis.
Sunnis and Shi'ites have a rivalry going back almost to the birth of Islam. Deobandis provide the ideological underpinning for the Taliban while Barelvis belong to Islam's moderate Sufi tradition. They have often clashed.
Other groups involved include the pro-Taliban Jamiat Ulema-e-Islam-Fazl (JUI-F) and the party of former cricket star Imran Khan. There are also banned groups such as the Lashkar-e-Taiba, involved in the 2008 Mumbai attack that killed 166 people, and Sipah-e-Sahaba, a virulently anti-Shi'ite group responsible for hundreds of deaths in the 1990s and 2000s.
Hatred of the United States has papered over differences.
"All religious parties today are together because of the Raymond Davis issue and attempts to change the blasphemy law," said Liaqat Baloch, a leader in JI.
Davis, an American CIA contractor, killed two Pakistani men in January. He said he was acting in self-defense and the United States says he has diplomatic immunity.
But Pakistan's government says the case, which has inflamed anti-American feelings, is for the courts to decide.
At the same time, suggestions a tough law against blasphemy be amended, to stop its being used unfairly against minorities, has enraged many Pakistanis.
Political analyst and author Ahmed Rashid said support for the religious parties had grown thanks to those issues and a failing economy.
"The mood is running very much against the existing parties, which are pretty failed," he told Reuters.
"I think they see that if they (religious parties) go down the electoral path ... they see themselves winning more seats in parliament."
The religious parties are riding what U.N. human rights chief Navi Pillay said was a rising wave of extremism "poisoning" Pakistani society.
For decades political rulers and security agencies have courted and even nurtured religious parties for their own ends.
The new-found unity among the factions comes as relations between the U.S. and Pakistani security agencies have been strained by the Davis case and by U.S. pressure on Pakistan to go after Afghan factions sheltering in Pakistani border enclaves.
At the same time, the civilian government that came to power after 2008 elections is beset by infighting, Islamist attacks and economic crises and appears too weak to stand up to the religious parties.
The growing extremism has led to the assassination of Punjab governor Salman Taseer and minorities minister Shahbaz Bhatti in January and March, both of them killed for calling for changes to the blasphemy law.
The government has responded by reassuring religious leaders it wouldn't touch the law.
President Asif Ali Zardari says his government has to treat the extremists carefully.
"The religious fanaticism behind our assassinations is a tinder-box poised to explode across Pakistan," Zardari wrote on Sunday in a Washington Post commentary.
"Our concern that we avoid steps that inadvertently help the fanatics is misinterpreted abroad as inaction or even cowardice.
"Instead of understanding the perilous situation in which we find ourselves, some well-meaning critics tend to forget the distinction between courage and foolhardiness."
(Additional reporting by Robert Evans in Geneva, Mubasher Bokhari in Lahore and Asim Tanveer in Multan; Editing by Robert Birsel and Miral Fahmy)