– President Vladimir Putin submitted constitutional amendments Monday that empower a previously toothless advisory council as a powerful policy arbiter, setting up what could be a future role for himself as Russia's long-term paramount leader.

Short on vital details, the proposed changes shed little light on Putin's exact plans and set off another round of speculation about the future of Russia's longest serving leader since Josef Stalin.

The amendments sharply increase the role of the State Council, turning what is currently a largely decorative body into a new locus of power that will "determine the main direction of domestic and foreign policy." Not specified, however, is how the council's head will be chosen and whether the body will be subordinate to the presidency.

The council is chaired by Putin in his role as president, a position that he first took when President Boris Yeltsin resigned on New Year's Eve 1999. But Putin is barred from seeking re-election once his current term runs out in 2024. His constitutional changes, first announced in a state of the nation address last Wednesday, are widely viewed as an effort to prolong his hold on power after the end of his term.

In another development in Russia's long somnolent but suddenly fast-moving political scene, Putin on Monday removed the prosecutor general, Yuri Chaika, a central pillar of the country's capricious law enforcement system throughout his 20-year rule.

The sudden flurry of changes has spawned a host of often contradictory theories about what Putin is up to and why he is moving so fast to reshape a political order largely unchanged for more than quarter of a century.

One theory is that, as a former KGB agent, Putin has embarked on a lightning "special operation" that, swift and unexpected, aims at subduing potential resistance by not giving time for anyone to figure out what is happening. Another unsubstantiated ­theory is that he could be ill and needs to move quickly before he is forced to bow out.

But, said Ivan Kurilla, a political analyst in St. Petersburg, Putin's hometown, "the most plausible explanation is that he wants to become the elder statesman who still holds power like the former Chinese leader or Nazarbayev," references to the late Chinese leader Deng Xiaoping and to Nursultan Nazarbayev of Kazakhstan.

Nazarbayav stepped down as president of that Central Asian country last year after nearly three decades. But he retained his influence by assuming the new title of "leader of the nation" and declaring himself chairman for life of a strengthened Security Council.

After Putin announced his proposed constitutional changes last week, Prime ­Minister Dmitry Medvedev and his entire government promptly resigned, giving Putin a free hand to reappoint ministers or name new ones. That process is expected to start this week.

Monday's removal of the prosecutor general, Chaika, indicated that the shake-up would extend beyond the ­Cabinet. Chaika, a former justice minister and senior prosecutor since shortly before Putin took power, is being moved to another, so far unspecified position, the Interfax news agency reported.

Taking over his powerful post as prosecutor general, roughly the equivalent of the U.S. attorney general, is Igor Krasnov, deputy head of Russia's version of the FBI.