The U.S. is offering up to $10 million for information on those who carried out a 2017 ambush in Niger, killing four American soldiers and four of their Nigerien counterparts. The State Department announced the incentive, offered through its Rewards for Justice program, Friday, on the two-year anniversary of the attack. Officials are seeking information leading to the identification or location of Adnan Abu Walid al-Sahrawi, the leader of the Islamic State in the Greater Sahara, which claimed responsibility for the...