In the first Iberian-American summit conference to be staged in Cuba, leaders from Latin America, Spain and Portugal have made one point abundantly clear: Their policy of engagement toward President Fidel Castro in the face of U.S. efforts to isolate him is not a one- way street.

Castro has touted the presence here of heads of state and other leaders from 21 countries as a diplomatic coup. But the coup has come with a price: At least eight visiting dignitaries have gone out of their way to hold unprecedented meetings about human rights with Cuban dissidents. Castro has suppressed dissent since coming to power four decades ago.

Although he told arriving leaders they could hold talks with whomever they pleased, Castro warned the anti-government activists of possible legal consequences for them. But in the end, analysts said, the aging president had little choice but to allow the discussions or risk straining relations with some of the countries that have become important economic partners for Cuba since the collapse of the Soviet Union.