Should the U.S. prevent Russia from conducting airstrikes in Syria?

In late September 2015, the Russian army conducted its first airstrikes in Syria and claimed they were intended to target ISIS positions within the country. U.S. military leaders and the Obama administration immediately warned that Russia is a close ally of Syrian President Bashar al-Assad and that the Russians will eventually turn their airstrikes against Syrian rebels who were recently supported by the U.S. Opponents of any further intervention in Syria argue that U.S. efforts to train rebels have failed miserably and we should stay out any further conflict in the region.