When Boris Yeltsin made his shocking New Year's Eve announcement that he was resigning, he emphasized that the decision was his and he had "contemplated [it] long and hard."


But not everyone believed him.


Insiders said the move - which leaves Prime Minister Vladimir Putin to run the country at least until presidential elections are held, and likely for the next four years - had long been plotted. Outside observers said Yeltsin was likely pressured to relinquish power.


Yeltsin's early retirement looks to have guaranteed that Putin, whom Yeltsin had previously named his preferred successor, will ride his current popularity to the presidency. Elections must now be held within three months, instead of in June as originally scheduled.


While politically expedient for Yeltsin and his entourage - who have been plagued by corruption allegations over the past year and apparently trust Putin to continue protecting them - the move seemed out of character for Yeltsin, who has been widely characterized as reluctant to give up power.


In his television address, aired at noon Friday, Yeltsin, 68, acknowledged that he had not envisioned such an end to his presidency.


"I would have liked the presidential elections to have taken place on schedule in June 2000," he said.


But he said he decided otherwise in order to clear the way for Putin.


"Why hold on to power for another six months, when the country has a strong person, fit to be president, with whom practically all Russians link their hopes for the future today? Why should I stand in his way?" Yeltsin said.


On the roller coaster of Russian politics, Putin, 47, could lose his overwhelming popularity before June, but he is unlikely to fall out of favor by March 26, the likely date for early presidential elections.


Yeltsin's dramatic speech, in which he apologized to the country for not fulfilling the hopes of the past decade, must have been prepared far in advance, observed Lilia Shevtsova, a political analyst at the Moscow Carnegie Center.


"This step was forced by the logic of this regime, a regime of elected monarchy," Shevtsova said.


But it was unclear to what extent the decision to resign was Yeltsin's and what role was played by the Kremlin's back-room players, known as "the family."


Both Yeltsin spokesman Dmitry Yakushkin and Igor Shabdurasulov, the Kremlin's first deputy chief of staff, were quoted as saying Yeltsin made the decision independently.


But one Kremlin insider, Unified Energy Systems head Anatoly Chubais, told Newsweek the idea of an early resignation for Yeltsin "was known and discussed." But, he said, "I was not sure that Yeltsin himself was ready for such a decision."


Former Soviet President Mikhail Gorbachev said Yeltsin was forced to step down against his will.


"He resisted with all his might. Essentially they pushed him," Gorbachev was quoted as saying by the Italian newspaper La Stampa. He named the architects of the resignation as Yeltsin's daughter Tatyana Dyachenko, tycoon Boris Berezovsky and Kremlin chief of staff Alexander Voloshin.


Gorbachev said the ailing president was convinced to resign by doctors who told him that staying in office could prove "fatal."


In Time magazine's Jan. 1 issue, Gleb Pavlovsky, one of the Kremlin's main election strategists, took credit for proposing the idea of Yeltsin's early retirement months ago. Time quoted Pavlovsky as saying that for the plan to work, the Kremlin needed to find a successor who could be trusted completely, and all other presidential contenders needed to be severely weakened.


The first condition was apparently fulfilled in August when Yeltsin appointed Putin, known to be much closer to "the family" than previous prime ministers. The second was met when pro-Putin parties prevailed over the Kremlin's biggest enemies in December's parliamentary elections.


Leon Aron, author of a just-released biography of Yeltsin, also pointed to the State Duma elections as being the key condition for Friday's events.


"At no time since 1990, when the Congress of People's Deputies of Russia first convened, has Yeltsin's agenda - democracy, private property, market economy - seemed as secure as they were after Dec. 19," Aron said. "It was his chance to retire, like [France's Charles] de Gaulle in 1970, undefeated - and he took it!"


But the corruption charges swirling around Yeltsin and his family may have played an important role.


Newsweek quoted unnamed sources as saying the decision about Yeltsin's resignation was made on Dec. 24 - the same day prosecutors announced they were extending the investigation into allegations that Kremlin officials, and Yeltsin's daughters, received bribes from the Swiss construction firm Mabetex.


On Friday afternoon, acting President Putin signed a decree granting Yeltsin immunity from criminal prosecution. While the immunity presumably does not extend to Yeltsin's family and associates, under the decree Yeltsin's home and office cannot be searched.


As Yeltsin made his speech in front of a decorated New Year's tree, he spoke slowly, his voice heavy with regret. At one point, he appeared to wipe away a tear.


Afterward, television footage showed Yeltsin welcoming Putin into the Kremlin room where the aging leader has appeared less and less frequently during his second term.


"Your office," he said, gesturing toward the desk.


The footage also showed the so-called nuclear briefcase being handed over to Putin. Yeltsin relinquished control over the case, which contains the controls that can activate the country's nuclear missiles, only once, briefly, when he underwent heart surgery in 1996. As soon as the anesthesia wore off, he was reported to have demanded the decree that he needed to sign to get his powers - and the suitcase - back.


While it was odd to see Russia's feisty first president stepping down and admitting failure, Yeltsin's timing seemed very much in character.


NTV television commented that it would have been difficult to imagine Yeltsin calmly waiting until the summer and then giving up power on schedule. Instead, he made his retirement an event, linking it to the new millennium.


"Boris Yeltsin resigned the way he worked," Communist leader Gennady Zyuganov told journalists. "He couldn't just let people relax and enjoy New Year's."