Victor Davis Hanson muses in his latest column at National Review Online about the impact of current American foreign policy on the future likelihood of war.

This bipartisan activist policy is coming to a close with the new “lead from behind” policy of the Obama administration. Perhaps America now believes that the United Nations has a better record of preventing or stopping wars — or that the history of the United States suggests we have more often caused rather than solved problems, or that with pressing social needs at home we can no longer afford an activist profile abroad at a time of near financial insolvency.

Yet the reasons for our new isolationism, analogous to early 1914 or 1939, do not matter; all that matters is the reality that lots of bad actors now believe that the United States cannot or will not impede their agendas — and that no one else will in our absence. Americans are rightly tired of the Afghan and Iraq wars. Yet we left no monitoring force in Iraq and are winding down precipitately in Afghanistan, and thus have no guarantees that our decade-long struggle for postwar consensual government will survive in either place.

Much of North Africa is beginning to resemble Somalia. Our tag-along strategy in Libya resulted in sheer chaos, with an American ambassador and three others killed in Benghazi. The Muslim Brotherhood, headed by anti-Semite Mohamed Morsi, has turned Egypt into a failed state. Islamists killed dozens of Western hostages in Algeria. The French are unilaterally trying to prevent an Islamist takeover of Mali. Meanwhile, 60,000 died in Syria, with thousands more fatalities to come.

The common theme? Middle East authoritarians and Islamists expect that the United States will probably lecture a lot about peace and do very little about war.