The United States transferred five detainees from the military prison at Guantánamo Bay, Cuba, to Kazakhstan, the Defense Department announced late Tuesday. It was the last in a flurry of year-end moves as President Obama sought to fulfill his promise to close the American-run prison. The five former detainees — three Yemenis and two Tunisians — are “free men” for all intents and purposes after the transfer, a senior official in the Obama administration said. Officials declined to disclose the security assurances reached between the United States and Kazakhstan or detail how the men would be prevented from returning to...