They're trying to eliminate as many military targets as possible before they are used against not only the military, but innocents. With this comes the collateral damage, especially when a regime hides it's military withing civilian areas. If they didn't have intel, those leaders would still be alive, but any intel comes with taking a chance it's legitimate. In this case it has been many times, and in the school case, not the right building. Very sad this happened, and hopefully not again, but it's the chance you take when you're trying to eliminate as many military targets as possible as fats as possible.
