This could allow the release of the most dangerous prisoners whom Israel has refused to free since the last big exchange in 2011, including convicted terrorists. A source close to the negotiations told The Times that the lead Hamas negotiator, Khalil Al-Hayya, was holding firm to Palestinian demands to release Barghouti and other high-profile prisoners. The source believes Hayya may be motivated by the killing of his son in the Israeli strike on a Hamas compound in Doha, Qatar, last month. As well as Barghouti, a senior leader of the Fatah movement who has been behind bars for more than...