FACTBOX: What next in plummeting U.S.-Venezuelan ties?

(Reuters) - U.S.-Venezuela ties plunged to their lowest point in years on Friday as the superpower and one of its top oil suppliers ejected each other's ambassadors.

The United States also imposed sanctions on Venezuelan officials, and leftist President Hugo Chavez threatened to stop selling crude to his main customer.

Here are some possible scenarios of how the relations could proceed:

STATUS QUO

Chavez could feel that for now he has gone far enough in stirring a crisis in a Venezuelan election year and may avoid escalating the dispute with any new retaliatory measures.

The United States could also calculate that fresh moves of its own would provoke Chavez to cut oil supply at a time when U.S. voters ahead of the presidential election are concerned about high oil prices.

DIPLOMATIC TIES

Chavez could cut formal diplomatic relations with the United States, recalling all of his diplomats. That would possibly trigger a tit-for-tat move from Washington.

In a diplomatic dispute with U.S. ally Colombia earlier this year, Chavez broke off ties and said they would not be restored until President Alvaro Uribe left office. Within months, he had made up with his neighbor and ties were fully re-established.

Chavez said he will not send an ambassador to Washington before Bush leaves office in January.

OIL SUPPLY

Chavez could cut off oil supplies to the United States. That would send oil prices higher, at least initially, but industry analysts say it could hurt Venezuela more than the United States.

Venezuela cannot quickly find new customers for its sludgy crude that is taken at U.S. refineries that have been specially-developed to upgrade its quality.

For years, Chavez has issued conditional threats that he could stop selling crude to America -- his biggest customer. On Thursday, he said if he were to do so, world oil prices would double to above $200 a barrel.

Chavez has diversified his oil customers in recent years, particularly increasing supply to China. He says the move is to shield the country from economic fallout should he ever feel obliged to stop U.S. sales.

Still, generally, Chavez has been a reliable oil supplier to the United States despite tensions.

Earlier this year, Chavez ordered a symbolic cutoff of sales to Exxon Mobil after the largest U.S. oil company brought a $12 billion lawsuit against the country for its nationalization of a project it ran in the OPEC nation. That cutoff hardly affected world prices.

AIRLINES

This week, the two countries resurrected a dispute over airline safety. The United States warned American passengers it could not vouch for security at Venezuelan airports and Chavez retaliated by ordering U.S. carriers to scale back their flights to the South American nation.

Chavez could flesh out details of his order, slashing scores of flights. In the past, the United States has downgraded its safety ratings for Venezuelan airlines, limiting their ability to operate in the lucrative American market.

SANCTIONS

The Bush administration imposed sanctions on Venezuelan officials for allegedly helping Colombian Marxist rebels. This raises the specter of Washington eventually labeling Venezuela as a state sponsor of terrorism along with a small group of U.S. foes such as Iran and North Korea. Chavez has anticipated such a move and told the United States where it can "shove" its list.

The Bush administration has in the past also blacklisted Venezuela for what is says is Chavez's failure to do enough to prevent drug and human trafficking.

MILITARY

The United States has already imposed some sanctions against Venezuela, such as preventing military suppliers from helping the country to repair aircraft equipment.

Chavez is angry the United States has reactivated a navy fleet to patrol the region for the first time in decades. He responded by aligning himself with Russia's armed forces. Two Russian bombers flew to Venezuela this week and Russia will hold navy exercises with the country in the Caribbean this year.

The symbolic flexing of military muscles could lead to more shows of force on both sides.

While political analysts see a military conflict as highly unlikely, Chavez constantly warns that the United States wants to invade, possibly through a proxy such as Colombia.

In March, he ordered tanks and troops to the Colombian border, saying in part it was to deter such a scenario.

(Reporting by Saul Hudson; Editing by Kevin Gray and Kieran Murray)