Editor’s Note: Julian Zelizer is a professor of history and public affairs at Princeton University, a New America fellow and author of “The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society.” The opinions expressed in this commentary are his.

Story highlights

Political debate over fight against ISIS is at fever pitch, writes Julian Zelizer

He says the United States should focus on key questions about the battles ahead

CNN  — 

The political debate over the fight against ISIS is at fever pitch.

Very soon after ISIS committed its atrocity in Paris, Republicans were criticizing President Barack Obama for his policies in Syria and Iraq. The Republican candidates joined in a chorus to explain what went wrong. Obama, they said, pulled troops out of Iraq too early, creating a vacuum that ISIS has filled while the administration failed to use enough force when Syria started to break apart.

In his characteristic rhetoric, Donald Trump said that if he were president, he would “bomb the s—t out of ISIS.” Candidates have come down hard on Obama’s refusal to call this a war against “radical Islam.”

Sen. Marco Rubio said, “I don’t understand it. That would be like saying we weren’t at war with Nazis because we were afraid to offend some Germans who may have been members of the Nazi party, but weren’t violent.”

When foreign policy and politics mix, which they almost always do, it can produce bad results.

Ongoing Republican attacks in the 1950s that Democrats were weak in the fight against communism, which conservatives said had been the reason that China fell in 1949, constantly put pressure on Democrats to prove that they were hawkish enough.

Politics was a big part of the reason that John F. Kennedy and Lyndon Johnson got the nation deeper and deeper into Vietnam.

Political pressure was also a major factor when Democrats in 2002 and 2003 shied away from asking tough questions about President George W. Bush’s decision to go to war in Iraq. Hillary Clinton and John Kerry, both future presidential candidates, voted in favor of a resolution allowing the president to use force even though there were many doubts, which proved correct, about whether this was really essential to the war against al Qaeda.

But there can be benefits when foreign policy becomes a major political issue. The good thing about elections is that they push politicians to confront and debate issues, to outline the differences that exist between and within the parties and to put people on the record as to how they would tackle a particular problem.

With ISIS, despite all the partisan friction, there is general agreement on who the enemy is and that they need to be defeated.

Yet there are legitimate questions about how to handle this national security challenge. As we move down the path toward a much bigger military operation, the nation could benefit from a robust debate among presidential and congressional candidates as to how we can defeat this enemy while protecting the democratic values that we cherish.

There are a number of questions that should be part of our political conversation in the coming weeks.

Should the U.S. commit greater military forces?

There is substantial support for adjusting the policies that President Obama has pursued. Democrat Clinton has come out with her proposal to enforce a no-fly zone over Syria, to conduct more airstrikes and to deploy additional special operations forces, all of which would require a much greater military presence by the United States.

But some Republicans, including South Carolina Sen. Lindsey Graham and Arizona Sen. John McCain, have also called for ground troops to supplement the airstrikes and the local forces upon which the U.S. been depending. This will be a critical decision. After years of war fatigue from the long conflicts in Iraq and Afghanistan, this would be politically difficult. The candidates should be asked under what situations would they be willing to move forward with such a deployment.

How will the U.S. pay for this?

A major escalation of military operations will cost money. This is the kind of question that politicians never talk about, yet it’s a question that always becomes central as military operations unfold.

The tensions between guns and butter have been a persistent challenge during times of military conflict. Often skyrocketing deficits have been the product of a nation unwilling to actually pay for its military interventions.

Republicans have been standing pretty firm that they will not raise taxes, and Democrats, thus far, have not explained where they would obtain added revenue or budget cuts to pay for a change in policy.

Where will the money come from should be something that candidates are forced to discuss now rather than once we are deep into the battle.

Assad or ISIS?

This probably the most urgent decision that the candidates will need to take a stand on. Thus far, President Obama has attempted to fight a two-pronged war against both the Assad regime in Syria and ISIS, which most experts agree is not possible.

Policymakers must decide whether the United States should concentrate on first using its force to take down Bashar al-Assad, and then move in on fighting ISIS in that region. Or should the U.S. possibly ally with Russia and Iran, leaving Assad in power, to focus everything on the war against ISIS? Right now, most of the pressure is moving politicians toward concentrating on ISIS.

What’s the diplomatic strategy against radical jihadists?

An ideological war can’t just be fought on the military battlefield. T

o really defeat ISIS, the United States needs to improve its diplomatic efforts to win over the hearts and minds of those who can possibly be recruited into these forces and to build support within local populations to help fight this threat. This is one of the reasons why some politicians have argued that turning away refugees will only play into the propaganda of ISIS about the United States and its allies.

At this point, ISIS has been more successful on this front than the United States, particularly in its use of social media to recruit members. The candidates should be asked about what specific changes they would make to our diplomatic efforts so that the United States can be more effective in the struggle to win over hearts and minds.

How to balance civil liberties and surveillance

Other than Rand Paul warning against a massive expansion of surveillance power and others saying that Edward Snowden is to blame for all of this, we haven’t had much of a careful discussion about how we can correct any intelligence gaps that exist without further diminishing civil liberties that have eroded since 9/11.

“I think we need to restore the metadata program,” Jeb Bush said on MSNBC’s “Morning Joe.”

It is not yet clear that a failure to collect data was the reason for the breakdown that resulted in Paris. In The Atlantic, Kaveh Waddell argued that it’s not clear new encryption techniques were the reason that intelligence officials missed this attack, nor is it clear that undercutting protections of the civil liberties of innocent Americans would actually benefit the war against ISIS.

The key issue is this: Can the rules under which the NSA operates allow it to monitor terrorists without creating a police state? That discussion needs to happen now, not after the United States plunges further into battle.

These are some of the central issues the nation faces, and that political candidates must be forced to deal in the public arena and with the intense scrutiny that comes in the midst of a campaign.

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