President Vladimir Putin will travel to Minsk next week hoping to finalise a deal that would unite Belarus and Russia into a single state and, perhaps, give Putin a new lease on power as head of the new country.
"This is a very serious development," says Sergei Markov, a Kremlin-connected analyst. "Majorities in both countries want this reunification, and it makes a lot of sense from the security and economic viewpoints."
The Kremlin has announced that Putin and Belarussian leader Alexander Lukashenko will meet next Thursday in Minsk to discuss the terms of the proposed new state's Constitution.
Experts say the arrangements are not yet finalized, but could involve the smaller Belarus amalgamating with huge, oil-rich Russia in much the same way Hong Kong was recently restored to Chinese sovereignty.
Belarus, with about 10-million people, is giant Russia's closest ally in the former Soviet Union and has long been dependent upon Moscow for energy supplies, security assistance and economic subsidies.
The two countries have been discussing the possibility of re-unifying for years, though talks have always stalled in the past over government structure, division of powers and the degree of sovereignty that Belarus would retain.
"The biggest obstacle to reunification is Lukashenko, who fears he'd lose power in a big Russia-Belarus union," says Markov. "They haven't come to a solution yet, but it could be close."
A new Russia-Belarus state, with a new Constitution, might enable Putin to set aside the previous Russian Constitution that limited him to two terms in office in order to become leader of the new super-state.