U.S. President Barack Obama's plan to bomb Syria for alleged use of poison gas has raised two questions that remain pertinent despite the proposed international monitoring and eventual destruction of that country's chemical-weapon arsenal: Is gassing people more inhumane or reprehensible than killing with conventional weapons? And are chemical weapons inherently prohibited in international law, just like genocide and slavery?

These questions are also important because Obama's request to Congress for authorization to attack Syria was not about any specific threat to U.S. or international security. Rather, the planned attack was intended for retribution to save the president's credibility that he believed was on the line.

Let's be clear: Chemical weapons — including choking agents like chlorine gas, blister agents such as mustard gas, arsenic- or cyanide-based blood agents, and nerve agents like sarin — are far less effective than modern conventional weapons, which kill with greater precision and lethality.