About half the aid is humanitarian. There are some 7m refugees who have fled the country and many more that remain and need basic assistance. What ever is the benefit to helping people in need? I can't give you what you want, which is a monetary number that is positive in our direction.
The other half is military aid. Someone pointed this out a few posts ago, and I did the same about 100 pages ago. We get see how our high tech weapons work on a major army with traditional military capabilities. We learn tactics, both those that work and those that don't. We get to see military capabilities of other countries with national slogans like "Death to America"- looking at Iran and NK. In that respect, it is a game, but again, there is no monetary number on the benefit.