This is not the first time in recent years that the United States has sought to draw up a list of Syrian government targets for a potential military strike. After all, the United States and its allies almost launched a considerable military operation following the 2013 Eastern Ghouta chemical weapons attack — the crossing of the now famous "red line" that brought the administration of then-President Barack Obama to the brink . Beyond the substantial attrition that the loyalist forces have suffered since then, there is one key factor that has completely altered the strategic picture for a U.S. strike in Syria. That is the arrival of the Russian military to Syria in 2015. There was a significantly more comprehensive list of military options available to the United States in 2013; it has fewer options today in light of the Russian presence.