Leading article: An unequal, but hopeful, exchange

By any standards, it was the most bizarre of prisoner exchanges, nor was it even really an exchange. The Israeli authorities agreed to free 20 Palestinians in return for a video tape showing that their soldier, Gilad Shalit, was still alive. The recording, which showed the sergeant looking healthy and reading a recent newspaper, was duly delivered, and 19 of the prisoners were released yesterday. The 20th is to follow tomorrow.

Unequal the exchange might have been, but the fact it happened at all sends a number of – mostly encouraging – signals. The first, and most obvious, is that Sgt Shalit, who was captured by Hamas militants more than three years ago, is indeed alive and ostensibly well. There had been fears that he might have been killed – fears that mounted after Israel invaded Gaza at the start of the year. It is now certain that he was not killed.

The second is that Hamas was prepared to go the extra mile. This is the first communication Israel has received from Sgt Shalit for more than a year, and the only visual proof ever. Since his capture, the Israelis have received only three letters and an audio tape. The video is conclusive in a way the earlier evidence was not.

And the third is that channels of negotiation between Israel and Hamas militants are open and functioning, despite Israel's official refusal to talk to Hamas. Egypt had mediated for three years with little to show for its efforts. Germany offered its services earlier this summer. Between them, progress now seems to have been made.

The deal looks unequal, and it is. But Israel has always placed an extremely high value on its own captured soldiers, a stance which has, in turn, driven up the price. This may be one reason why Sgt Shalit is still alive. Hamas cannot afford to squander the life of a prisoner for whose freedom it has demanded the release of 1,000 Palestinians.

The Israeli Prime Minister, Benjamin Netanyahu, while cautiously optimistic, warned again yesterday that Sgt Shalit's freedom was probably still a long way off. But the fate of this one soldier has also become a touchstone for the state of Israel-Palestinian relations more generally. And in both respects, yesterday's trade marked an advance.