Because it worked so well in Vietnam?
The president hasn’t yet given the green light for an attack on Islamic State militants in Syria, but the U.S. military campaign against the group there is being designed to allow President Barack Obama to exert a high degree of personal control–going so far as to require that the military obtain presidential signoff for strikes. The requirements for the strikes will be far more stringent than those targeting Islamic State in Iraq, at least at first. U.S. officials say it is an attempt to limit the threat the U.S. could be dragged more deeply into the Syrian civil war. After meeting with his top military advisers in Tampa yesterday, Mr. Obama insisted anew that U.S. ground forces won’t engage in combat in Iraq or Syria, despite suggestions by top military commanders that conditions could one day require that U.S. advisers and other military units play a limited front-line role (Here’s a look at why troops in Iraq don’t count as boots on the ground). Julian E. Barnes and Carol E. Lee report.