Can a Divided America Still Lead?

03/13/2015 01:51 pm ET | Updated May 13, 2015

The Iran issue highlights a central dilemma of U.S. foreign policy: will political division undermine U.S. world leadership?

In his Second Inaugural Address in 1997, President Bill Clinton said, "America stands alone as the world's indispensable nation.'' Since World War II, whenever there has been a threat to international order or humanitarian values, the rule has been that if the United States doesn't do anything, nothing happens.

If the U.S. had not led a coalition to force Saddam Hussein out of Kuwait in 1991, Kuwait would now be a province of Iraq. If the U.S. had not used force against Serbia in 1998, ethnic cleansing would have wiped out the Muslim population of Kosovo. If the U.S. had not disarmed Libya's air defenses, Muammar Qaddafi would still be in power. The U.S. did nothing in Cambodia or Rwanda or Congo or Darfur, and the result was genocide.

Right now, there are several major threats to world order and humanitarian values. ISIS is one. A potentially nuclear Iran is another. Vladimir Putin's aggression in Ukraine is a third. The world, as usual, is relying on the United States to do something. The U.S., as usual, is reluctant to get involved.

Certainly not in Ukraine, even though military force may be the only way to stop Russian aggression. Ukraine can't defeat the Russian army. The European Union is trying, haplessly, to arrange one cease-fire agreement after another. War with Russia is unthinkable to Americans, but Putin would not take kindly to the U.S. supplying Ukraine with weapons that would be used to kill Russians.

Americans are horrified by ISIS atrocities and appear willing to take on the ISIS threat. The Quinnipiac Poll found a majority of better than two to one in favor of "sending ground troops to fight ISIS in Iraq and Syria.'' President Obama is following a more cautious strategy of using U.S. air power and relying on proxies to do the fighting on the ground. Ironically, Iran has taken the lead in the ground offensive against ISIS.

President Obama has asked Congress to give formal authorization for the use of military force against ISIS. Polls show the public is solidly behind the President's request -- 66 percent in last month's CBS News poll, 78 percent in a CNN poll. But Democrats and Republicans in Congress have been unable to reach agreement on the measure. Democrats are concerned the authorization goes too far. Republicans believe it does not go far enough.

When President Obama requested the authorization, he said, "The world needs to know we are united behind this effort.'' The message being sent to the world is precisely the opposite.

The U.S. is relying on diplomacy to block a nuclear threat from Iran. Both Israel and the Arab world are watching anxiously to see if the U.S. can deliver. Meanwhile, congressional Republicans, buoyed by the Israeli prime minister, are doing everything they can to sabotage the effort.

In the foreign policy world, the debate over the pending U.S. agreement with Iran centers on one issue: which option -- deal or no deal -- makes it less likely that Iran will get a nuclear weapon? In the world of U.S. politics, the debate is about a different issue: which option is less likely to draw the United States into another Middle East war?

When he addressed Congress, Israeli Prime Minister Benjamin Netanyahu argued that the pending deal "would inexorably lead to a nuclear-armed Iran whose unbridled aggression would inevitably lead to war.'' Both President Obama and Secretary of State John Kerry complained that Netanyahu failed to come up with an alternative that would not lead to war.

Netanyahu insisted that the alternative is not war but ``a much better deal.'' And how would that happen? Suppose the U.S. insists on the much tougher terms Netanyahu wants. ``If Iran threatens to walk away from the table,'' the Israeli prime minister told Congress, ``call their bluff. They'll be back because they need the deal a lot more than you do.'' That's a risk many Americans may not want to take.

Iran is now a battlefront in the civil war in American politics. That civil war is undermining America's ability to remain "the world's indispensable nation.'' Last month, the Pew poll asked Americans whether "using overwhelming military force is the best way to defeat terrorism around the world,'' or whether "relying too much on military force to defeat terrorism creates hatred that leads to more terrorism.'' The result? A split. Forty-seven percent of Americans endorsed "overwhelming military force'' and 46 percent believed military force was counterproductive. Three quarters of Republicans endorsed military force. Two thirds of Democrats expressed reservations.

Now we have a foreign leader exhorting Americans to "trust me, not your own President.'' The shock is, many Americans do.