A former CIA operative wanted for trial for acts of terrorism against Cuba is stuck in legal limbo in a Texas jail. Luis Posada, 78, who has allegedly taken part in plots to assassinate Fidel Castro and bomb Havana hotels, is being described as a test case of the US government's commitment to fighting terrorism.

Mr Posada, a Cuban opponent of President Castro who is a naturalised Venezuelan, is in jail in El Paso, Texas. He was arrested in Florida in 2005 on charges of entering the country illegally. He has been accused by Cuba and Venezuela of being part of a 1976 plot to blow up a Cuban airliner en route from Venezuela to Cuba with the loss of 73 lives. Both countries now seek his extradition to stand trial.

The US courts have ruled that Mr Posada should not be sent to Venezuela or Cuba on the grounds that he would not receive a fair trial and may face torture. Mr Posada has denied involvement in the airliner bombing, but has admitted being part of a plot to bomb Havana hotels, which led to the death of an Italian tourist. In addition, he was jailed for an assassination attempt on President Castro in Panama in 2000, although he was later pardoned by the Panamanian authorities.

For the Bush administration, committed to a "war on terror" and opposed to anyone "willing to harbour a terrorist or feed a terrorist", in the president's words, Mr Posada is an increasing irritation.

One solution was for him to leave the US for a country prepared to offer him a home. However, so far seven countries which have been approached - Canada, Mexico, El Salvador, Panama, Costa Rica, Honduras, and Guatemala - have all refused. Yesterday his lawyer in El Paso, Felipe Millan, said that situation remains unchanged.