Has the world entered a new era of chaos? America's vacillating policy toward Syria certainly suggests so.

Indeed, the bitter legacy of the invasions of Iraq and Afghanistan, followed by the 2008 financial crisis, has made the United States not only reluctant to use its military might, even when "red lines" are crossed, but also seemingly unwilling to bear any serious burden to maintain its global leadership. If America is no longer willing to lead, who will take its place?

China's leaders have demonstrated their lack of interest in active global leadership by openly rejecting calls to become a "responsible stakeholder" in the international political and economic systems. Meanwhile, though Russia may wish to maintain the illusion that it is a global power, it lately seems interested primarily in thwarting America whenever possible — even when doing so is not in its own long-term interests.