The unraveling of the conference displayed the deep ideological divide at the 193-nation gathering in Dubai, where envoys grappled with the first revisions of global telecom codes since 1988 - years before the dawn of the Internet age.
A Western bloc led by a powerhouse U.S. delegation sought to stop any U.N. rules on cyberspace, fearing they could squeeze Web commerce and open the door for more restrictions and monitoring by authoritarian regimes that already impose wide-ranging clampdowns. The head of one tech industry group said it could "forever alter" the Web.
A rival group - including China, Russia, Gulf Arab states, African nations and others - favored U.N. backing for stronger government sway over Internet affairs and claimed the Western dominance of the Internet needed to be addressed.
The battles were over language that could influence perceptions of what the Internet means as a modern tool for business, communications and societies - and not directly about specific practical regulations.
The head of the U.S. delegation, Ambassador Terry Kramer, described it as a "crossroads over the collective view of the Internet."
Many of the disputed clauses were quashed or watered down during 10 days of negotiations, but the non-Western bloc managed to win support for wording that supported governments' rights to have access to the Web.
This was viewed by the U.S. and its allies as a backdoor attempt to gain U.N. sanction for more government controls over the Internet, adding to earlier objections about references that could suggest U.N. backing for more state authority over content and commerce.
In a packed meeting hall, U.S. envoy Kramer said he could not sign the final accord, noting a "heavy heart and a sense of missed opportunities."
A host of Western nations - including Canada, Britain and New Zealand - also said they could not back the new charter by the U.N.'s International Telecommunications Union, or ITU, a group dating back to the birth of the telegraph more than 140 years ago.
"Internet policy should not be determined by member states, but by citizens, communities and broader society ... the private sector and civil society," said Kramer. "That has not happened here."
He bemoaned possible signs that the free-wheeling growth of the Internet could now be encumbered by government bureaucracies and security agencies.
"The Internet has given the world unimaginable economic and social benefits ... all without UN regulations," he told the conference.
The ITU has no powers to instantly change how the Internet operates and its regulations are non-binding. It also cannot compel reforms by states that already widely censor cyberspace.
But the U.S.-led coalition at the talks argued that any U.N. codes sanctioning greater government roles in the Net - even under the framework of state security - could be used as justification for even more controls from Web watchers in places such China, Iran and other nations.
The host United Arab Emirates announced stricter Internet laws last month that outlaw postings such as insulting rulers or calling for protests. The Iranian delegate at the talks said it was time for a more "balanced approach" between the Net's borderless reach and the needs of nations.
There is an outside chance that final text could be rewritten to appease the U.S. and others before the meeting closes Friday. But ITU spokeswoman Sarah Parkes said it "looks like a formality" that the document will stand.
"It's not a crime to talk about Internet inside the ITU," said the group's secretary-general, Hamadoun Toure, before Thursday's decisive session.
Toure insisted the treaty did "not include provisions" on direct Internet oversight by governments. But he noted the growing rifts over how to deal with the Net.
"There is no single world view, but several and these world views need to be accommodated and engaged," he said after the Western rejection.
The U.S. team in Dubai also includes heavy hitters from the tech world such as Microsoft Corp. and Google Inc., which stood up against proposals by European telecoms companies to charge Internet content providers for access to domestic markets around the world.
A statement from Google said the Dubai gathering underscored that "many governments want to increase regulation and censorship of the Internet."
"We stand with the countries who refuse to sign this treaty," said the company statement.
In Washington, State Department spokeswoman Victoria Nuland said the conference went in the "wrong direction" by opening the door to greater government controls "instead of focusing on promoting innovation and market growth in the telecom space."
Michael Beckerman, president and CEO of the Washington-based industry group The Internet Association, said the efforts for greater government controls could "forever alter" the current framework of the Net.
"The unique nature of the Internet - free from government control and governed by multiple stakeholders - has unleashed unprecedented entrepreneurialism, creativity, innovation, and freedom far beyond imagination," he said in a statement. "Preserving a free Internet for all people is essential to the preservation of political and economic liberty."
Other issues in the accord include calls for more transparency on roaming charges by mobile phone companies, efforts to fight Internet fraud and spam and creation of a worldwide emergency number for mobile phones and other devices.