Trump Sees the Political Value of War. He's Wrong.

(Bloomberg Opinion) -- If Donald Trump is currently wondering about the potential domestic political effects of a U.S. war in Iran, the answer is pretty clear: Don’t do it.

It’s certainly possible that Trump could benefit from a “rally around the flag” effect if war breaks out. But it’s by no means a sure thing. Political scientists have found that, as Richard Skinner put it: “Usually the rally-round-the-flag effect requires opposite-party elites to embrace the war (or at least not criticize it).” What’s important about that finding is what it doesn’t include. It turns out that whether a foreign crisis goes well or not isn’t really what determines the domestic political reaction. So for example George H.W. Bush got a huge bump in his approval rating when the Gulf War was won quickly and decisively – but so did Jimmy Carter when American hostages were taken in Tehran in 1979.

Trump himself bought into this assumption in 2011, when he predicted that President Barack Obama would attack Iran to score political points:

But a gamble on a war in Iran producing a surge in Trump’s approval ratings is really a bet that a fair number of Democrats in Congress and other highly visible Democrats would support the policy.

That’s certainly possible. Even if they all opposed such a policy at first, it’s always tricky for politicians to oppose a military operation while it’s under way. That’s presumably especially true if it’s going well – but it’s tricky to oppose even if it goes badly, at least at first.

Still there are good reasons to expect Democrats would be extremely reluctant to support hostilities against Iran. The faction of the party that tends to be anti-war to begin with almost certainly will line up against this one. Those who are more open to military adventurism are probably more likely than not to join them.

That’s to some extent the consequences of the Iraq War, which has made everyone more wary of wars of choice in that part of the world, especially given that many of the same hawks from 2002, including the national security adviser, John Bolton, would be the people selling a war in Iran now.

It’s partially a consequence of  Trump’s reputation, certainly among Democratic politicians, as a habitual liar. And it’s partially because Trump is so unpopular among Democratic voters that very few Democratic politicians want to back him on anything.

In all, a rally effect is certainly possible, but there are good reasons to believe it wouldn’t happen.

However, when it comes to domestic political consequences, the most important thing isn’t the immediate reaction; it’s the longer-term affect on public opinion. And for that, the prospects for Trump if he takes the nation to war are not good at all.

The problem for Trump is that if things go well, voters will have extremely short memories. That’s what George H.W. Bush found after the Gulf War. After Bush’s approval rating spiked up to then-record levels in early 1991, voters rapidly forgot all about the war and then turned on Bush when the economy slumped. A year later it was as if the war, widely seen as a major success, had never happened; soon after that, Bush was defeated for re-election. That was no fluke caused by a recession. The entire history of rally-around-the-flag effects is that they are temporary, and voters eventually care far more about the economy and other concerns back home.

Unless, that is, the war goes poorly. A drawn-out conflict is just about the worst thing a president can do for his or her approval rating, as Harry Truman found out in Korea, Lyndon Johnson found out in Vietnam, and George W. Bush found out in Iraq. And as George W. Bush can explain, that’s true even if the war initially goes well. (I suppose deliberately tanking the economy might equally harm a president’s popularity, but no president would ever do that, right?)

Of course, if world events leave a president no choice, then initiating military action may still be the best course despite all of that history. If so, the best thing a president could do would be to work hard to earn the trust of both parties in Congress, and then to figure out how to avoid prolonged hostilities if possible. It would certainly not be a good time to clash with the out-party over oversight, for example.

I suspect this is all contrary to the conventional wisdom. But it does seem to be a case in which the conventional wisdom just isn’t supported by the data. The best-case scenario for a Trump war would be a quick public opinion boost that’s probably long gone by November 2020 – and the downside would lead to a landslide loss for the president. If the administration really thinks military action is necessary, then perhaps that shouldn’t stop them – but doing it for domestic political reasons could easily be a colossal blunder.

To contact the editor responsible for this story: Philip Gray at philipgray@bloomberg.net

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Jonathan Bernstein is a Bloomberg Opinion columnist covering politics and policy. He taught political science at the University of Texas at San Antonio and DePauw University and wrote A Plain Blog About Politics.

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