Payá, the country’s most prominent Catholic voice, crossed a red line in challenging the government’s relations with the church, which had become a pillar of the government’s strategy of survival. He also did so at a time when the regime, emboldened by the cardinal’s silence at the mass arrests during the pope’s visit to Cuba in March, was not about to tolerate criticism.

Visiting Bayamo with foreigners — the two survivors of the crash were fellow Catholics from Spain and Sweden — crossed another red line. The city is the center of the cholera outbreak in the eastern part of Cuba, and for the regime, the disease is not just a medical problem but also an economic and political threat. The leakage of information about the outbreak threatens travel to Cuba and tourism, major sources of hard currency, which the regime desperately needs.

The spread of the disease also challenges Cuba’s self-image as a medical superpower and could arouse anger in citizens who believe that sending Cuban doctors to Venezuela and other countries detracts from the care they receive at home. The fact that Bayamo has experienced labor unrest the past two years and was a rebel stronghold during Cuba’s war of independence against Spain and the uprising against Batista further arouses the regime’s anxiety.

In the coming days, more facts are likely to emerge about Payá’s death. The testimony of the two survivors will be critical. As the United States and other democratic governments mourn Payá, it is essential that they — and world opinion — be alert to the dangers faced by democrats in Cuba.

Without international solidarity, more martyrs are likely in the struggle for Cuban freedom.

Carl Gershman is president of the National Endowment for Democracy.