EDINBURGH (TIP): Voters in Scotland rejected independence from Britain in a referendum that had threatened to break up a 307-year union, according to projections by the BBC and Sky early Friday, September 19. The outcome was a deep disappointment to the vocal, enthusiastic pro-independence movement led by the Scottish first minister, Alex Salmond, who had seen an opportunity to turn a centuries-old nationalist dream into reality, and forced the three main British parties into panicked promises to grant substantial new power to the Scottish Parliament.

The decision spared Prime Minister David Cameron of Britain a shattering defeat that would have raised questions about his ability to continue in office and diminished his nation’s standing in the world. But while the result preserved a union molded in 1707, it left Mr. Cameron facing a backlash among some of his Conservative Party lawmakers. They were angered by the promises of greater Scottish autonomy that he and other party leaders made just days before the vote, when it appeared that the independence campaign might win.

Some lawmakers called for similar autonomy for England itself, and even the creation of a separate English Parliament. The outcome headed off the huge economic, political and military imponderables that would have flowed from a vote for independence. But it also presaged a looser, more federal United Kingdom. And it was unlikely to deter Scottish nationalists from trying again. The passion of the campaign also left Scots divided, and Mr. Salmond was expected to call later on Friday for reconciliation after a vibrant exercise in democracy that had episodes of harshness and even intimidation.

President Obama had made little secret of his desire that the United Kingdom remain intact. Indeed, Britain had long prided itself on a so-called special relationship with the United States, and Britain’s allies had been concerned by, among other things, Mr. Salmond’s vow to evict Britain’s nuclear submarine bases from Scotland, threatening London’s role in Western defenses.

As the vote approached, the margin between the two camps narrowed to a few percentage points, and at one point, the “yes” campaign seemed to have the momentum. That was enough to alarm Britain’s political leaders from the three main parties in the Westminster Parliament in London. In a rare show of unity, they promised to extend significant new powers of taxation to Scotland, while maintaining a formula for public spending that many English voters saw as favoring Scots with a higher percapita contribution.