In this July 23 photo, Iraqi Army soldiers with new U.S.-made weapons take combat positions at the front line in an eastern suburb of Ramadi, Iraq. (Uncredited/Associated Press)

Bing West is a former assistant secretary of defense and combat Marine and has written three books about the war in Iraq.

Is the United States at war? Even our top leaders do not know. At his nomination hearing last month to become the next Marine Corps commandant, Lt. Gen. Robert B. Neller was scolded by Sen. John McCain (R-Ariz).

“I’m disappointed for you not to be in favor of us having forward air controllers on the ground” in Iraq, McCain said.

McCain’s son fought as a Marine in Anbar province, where Neller organized the advisory effort that resulted in the Sunni Awakening. One would expect Marines to support action to retake the province where thousands of them died. So why this deep difference of opinion?

The senator demanded bombing by front-line American advisers. In contrast, the general said that the key advisory task was to “ensure the right Iraqi officers were put in charge.” The difference is significant. To defeat the Islamic State, do you increase the bombing or change the leaders?

Consider first the forward air controllers. A controller operates as part of a team of a dozen soldiers, plus vehicles, plus reinforcements on alert, plus aircraft for evacuations, plus logistics. To insert controller teams into the battles for Fallujah or Ramadi requires a commitment on the order of thousands of Americans.

Then comes the hard part. Urban battlefields are compartmented by long corridors of houses. Forward air controllers must designate targets inside apartment complexes only a few hundred meters up the street. By definition, advisers and air controllers are working in support of Iraqi units. The terrorists will hold civilians as shields. So who is responsible for deciding the rules of engagement and the risks to civilians? Is it the Iraqi captain screaming “Bomb!” or the U.S. lieutenant who is advising?

If the advisers are unwilling to bomb, they should not be there in the first place. If they do bomb, the American public must be prepared to witness a staggering amount of damage. In Fallujah in fewer than 20 days in 2004, the Marines launched 540 airstrikes and destroyed or heavily damaged about 18,000 buildings. In 2015, the Islamic State occupies a dozen cities. Those cities will be blasted.

Al Jazeera and other networks will provide graphic coverage of the damage. Some scenes will shock. Iraqi soldiers will execute Islamic State terrorists while advisers watch. And what if an American is captured and burned alive? If we send in air controllers, we are committing to war without a public consensus at home and with Iraqi and Iranian generals determining the battlefield strategy.

Now consider Neller’s caution about committing air controllers. He said that the U.S. military in 2006-2007 used its leverage to promote competent officers (“the right Iraqi officers ”). The Iraqi government dismissed them after our forces left in 2011. The Sunnis were then oppressed, and the Islamic State surged in. Today, the Iranian Republican Guard and its loyal Shiite militias exert more leverage in Baghdad than the United States. Given the pending nuclear deal, President Obama will not antagonize Tehran by challenging that power balance. Thus, we have no means of bringing back the competent, nonsectarian officers whom Neller cited .

The intelligence community, the military and civilian leadership in the Pentagon and the State Department all recommended leaving a residual force in Iraq. The president decided otherwise. Similarly, he promised the removal of the Bashar al-Assad regime from Syria, then did nothing as the Islamic State turned that nation into its lair. Now he confronts the tragic consequences. As commander in chief, only he can orchestrate the political, military and strategic components to wage a resolute war. He has declined to do so.

Given that reality, Neller exhibited prudence in not endorsing the infusion of advisers on the front lines. It does not assure victory; it does require coordination, however quietly and at arm’s distance, with Iranian forces. It places our forces under the de facto control of an untrustworthy Baghdad government. Deploying forward air controllers places us in the middle of a war that our commander in chief has no intention of winning. The administration will label this as impetuous warmongering: Ready, fire, aim. Republicans should not be advocating incremental escalation reminiscent of Vietnam.

Obama lacks a credible policy to support Sunni warriors and leadership backed by U.S. firepower. Our generals are rightly reluctant to avoid commitment in the absence of an achievable political end state and public support. A tactic is not a substitute for a strategy.