Leading article: The Obama effect reaches Cuba

Few people were probably more surprised than Barbara Lee and her US Congressional colleagues when they were suddenly invited to an audience with Fidel Castro during their recent visit to Cuba. The trip itself was a milestone in its own way: the group of Congressional Democrats had gone to Cuba to investigate ways of improving bilateral relations. But to meet the old warhorse himself, rarely seen in public since an extended hospital stay three years ago, must be interpreted as a propitious sign.

Ms Lee said the former Cuban leader appeared healthy, energetic and clear-thinking – an impression that counters recurrent reports that he is at death's door. More to the point, though, is what he is reported to have said to them: how could Cuba help President Obama normalise relations between their two countries?

In so saying, he sent two clear messages. The first was to Washington: that if Mr Obama honours campaign promises to work towards a better relationship with Havana, he will be knocking at an open door. The other message was for his fellow Cubans.

By giving the nod to a rapprochement, Fidel Castro has not only smoothed the path for his brother and successor, Raul, to welcome further moves in that direction, but conveyed to ordinary Cubans that the United States need no longer be treated as the ideological enemy No 1. Fidel's blessing is also a warning that a change of policy should not become a cause of dissension within the leadership.

If the ground for improved relations has to be thoroughly prepared in Cuba, something similar also applies in the United States. There will be some, not only in the exile community, who will fiercely oppose any change so long as anyone associated with Fidel Castro is still in charge. What might look to Europeans like an overdue injection of common sense into a mutually disadvantageous antagonism will still need careful political handling.

After a European tour that largely healed the transatlantic rifts over the Iraq war and missile deployments, while also paving the way for better relations with Muslim countries, Mr Obama is now expected to address problems closer to home, and one of those is Cuba. An end to the ban on travel to the island by Cuban-Americans is said to be imminent, along with the lifting of restrictions on remittances.

Both were campaign promises and both are within the President's remit. A bill lifting the ban on travel to Cuba by all US citizens is also before Congress. All these measures can be justified as a belated response to the relaxation that has taken place, especially in commerce, in the year since Raul Castro succeeded his brother.

The path to full normalisation will only be clear when the US trade embargo is lifted. This is more controversial and requires legislative approval. With goodwill on both sides, however – a prospect unthinkable until recent months – an end to one of the most stubborn Cold-War disputes could be in sight.