In Sarah Kreps, et.al. “Policy Roundtable 2-1: Public Opinion and the Trump Administration’s Foreign Policy,” International Security Studies Forum
When President Ronald Reagan donned his “I’m a contra too” T-Shirt back in the 1980s and dubbed the Nicaraguan anti-communist guerrillas “the moral equal of our Founding Fathers,” he and his advisors were convinced the American public would now support their effort to overthrow the Sandinista regime. They were wrong. They overestimated how malleable public opinion was even in the hands of the Great Communicator. Polls only shifted marginally. Reagan had to limit his policy to aid and covert operations, not more direct military action.
When in August-September 2013 President Barack Obama backed off his threat to retaliate against Syria if it used chemical weapons, claiming that even though the Bashar Assad regime had crossed that redline the American public would not support such action, he overestimated the public opinion constraints. Polls right after the revelations of chemical weapons use showed 50% willing to support limited military action. And this was without the rally effect that initially comes when a president puts himself behind a policy, since at that point Obama was only intimating that he might use force. It was only when Obama showed his own ambivalence, saying he had to go to Congress first, that public support fell off. When President Donald Trump retaliated for Assad’s April 2017 chemical weapons attacks with limited airstrikes, he received 57% support.
This gets at the basic constraints-malleability dynamic in which, as Bruce Russett characterized it, presidents cannot “persuade the populace to support whatever the leaders wish to do,” yet nor are they necessarily so constrained as to have to “obey [its] dictates.” How has this mix been playing out with public opinion and Trump’s foreign policy? I start with some specific issues and then look at broader ones (all as an early cut).
On NATO, China, and Israel, public opinion has been exerting a ‘centripetal pull,’ moderating the extreme positions Trump took during the election campaign. This is similar to the pattern Miroslav Nincic identified with the Carter and Reagan Soviet policies. Concerned about whether President Jimmy Carter was “tough” enough, the public expressed low levels of approval for his Soviet policy in its conciliatory phases (1977-1978, most of 1979), and higher levels of support when Carter got hawkish (1980). Reagan’s foreign policy reputation was plenty tough but raised concerns as to whether it was reckless and risked war. Thus, public approval of Reagan’s Soviet policy was low when it was most strident and confrontational (1981-1983), and then increased once Reagan became more open to cooperation, peaking at 65 percent following his first summit with the Soviet leader Mikhail Gorbachev in November 1985. 
On use of force issues, support for Trump’s policy seems to be consistent with the “pretty prudent public” pattern based on a greater disposition to be supportive when the principal policy objective is perceived as anti-aggression foreign policy restraint than for remaking governments and other internal political changes. The support for the air strike retaliating against Syrian use of chemical weapons fit the anti-aggression foreign policy restraint objective. So does the high levels of support for anti-Islamic State (ISIS) military action: 72% for the use of airstrikes and 57% for special operations, prudence kicking in for only 42% for combat troops. But when it comes to the Syrian civil war, an internal political change objective, even just providing arms and supplies to anti-government forces gets only 26% support.
The deliberations on Afghanistan war troop levels, ongoing as of this writing, appear to be holding to the same pattern. By 2014 more Americans deemed the Afghanistan war as a mistake than did not. What had originally been seen in the wake of 9/11 as anti-aggression had come to be seen as largely about remaking a government. The public agreed with Obama’s troop withdrawal by a ratio of 4 to 1. Even though the rise of ISIS along with Taliban gains led Obama to delay the troop drawdown, Trump’s re-opening of the question as to whether to further increase troop levels has not been gaining public support: a June 2017 poll posing a 4000-troop increase got 25% support, 45% opposition.
A more meta-issue on which the dynamics are quite different from the past is Trump getting away with challenging the cherished notion of American exceptionalism. Obama was attacked when early in his presidency rather than the usual ‘City on a Hill’ invocation, he made the more qualified statement that “I believe in American exceptionalism, just as I suspect that the Brits believe in British exceptionalism and the Greeks believe in Greek exceptionalism.” In his rational-analytic manner he elaborated: “The fact that I am very proud of my country and I think that we’ve got a whole lot to offer the world does not lessen my interest in recognizing the value and wonderful qualities of other countries, or recognizing that we’re not always going to be right, or that other people may have good ideas.” Republicans quickly and loudly attacked him for being un-American. ‘The Blob,’ too, as Obama memorably derogated the bipartisan foreign policy establishment, criticized him for violating its creed cum conventional wisdom. Yet when Trump was asked by Bill O’Reilly on Fox News how he could be so favorably disposed to a killer like Russian President Vladimir Putin, he responded, “We’ve got a lot of killers, too. What do you think? Our country’s so innocent?” While this moral equivalence with the Soviets-Russians goes way too far, Trump is right that the reality of U.S. foreign policy historically as well as contemporaneously has fallen well short of the exceptionalist myth. Perhaps lessening the distorting effects of this myth could be one of the few helpful legacies of Trump’s foreign policy.
What are we to make of Trump’s overall ‘America First’ quasi-ideology? On the one hand the standard ‘stay out/take an active part’ poll question when re-fielded in June 2016 found 70% of Democrats and 64% of Republicans to be on the active part-internationalist side. On the other hand, America First was a big part of Trump’s appeal. It evokes less the traditional isolationism of pulling up the drawbridges and coming home than an assertive nationalism that imposes the costs and burdens of American hegemony and protection on others. It reflects the belief that the world owes America more than America owes the world, and that the United States will use its power at times and places and in manners of its own choosing. It is politically potent because it taps into three underlying trends.
First, it fits and exploits Republican-Democrat and intra-Republican divisions. On immigration only 27% of Democrats see it as a critical threat while 67% of Republicans and 80% of core Trump supporters do. On whether Islamic fundamentalism is a critical threat: 75% of Republicans agreed but only 49% of Democrats. On whether globalization is a good thing: 74% of Democrats agreed but only 59% of Republicans and 49% of core Trump supporters did. Trump’s scorching of the field in the Republican primaries showed how out of synch John McCain-type hawkism and Dick Cheney-type neo-conservatism had become. His general election defeat of Democratic nominee Hillary Clinton showed the limited appeal of liberal internationalism and its more consensual but still globally committed effort to run the world.
Second, America First taps sources of political discontent that run deeper than just a particular individual, issue, or election cycle. Indeed, notwithstanding differences in personalities and other particulars, there is a strikingly similar pattern in the United States and virtually all of Western Europe of three disruptive societal forces—economic discontent based on widening income inequality and narrowing economic opportunity, cultural anxiety caused by immigration and long-festering racial and ethnic tensions, and personal insecurity because of recurring terrorism at home—mixing together in a potent ‘witches’ brew’ posing profound challenges to world democracies.
Third, from an historical perspective the United States is at a crux. For much of its history the U.S. kept itself largely apart from the world. While not as isolationist as it is often depicted, insulated by the oceans and blessed by a bountiful land, it was able to selectively engage with the outside world when and where it chose. During the Cold War and its immediate aftermath, the U.S. sat atop the world. Militarily, economically, technologically, diplomatically, politically, ideologically—it was dominant by most every measure; indeed, with the fall of the Soviet Union it was the sole surviving superpower. Today, though, with insulation stripped away amidst globalization and dominance chipped away as other countries assert themselves, Americans find themselves neither apart nor atop but rather amidst the world, both shaping and being shaped by global events and forces. As formidable as are the policy challenges thus posed, even more fundamental is the shock to its very sense of self as a nation. It is in this context that Trump’s mix of reverting to being apart and re-asserting to be atop has been having its appeal to the national psyche.
In sum, while on some issues Trump has been moderating, I wonder whether that will continue. One gets the sense that he really does not much like Europeans, and is not convinced of NATO’s value, intentionally omitting affirmation of the Article V collective security commitment key advisors put in his June Brussels speech and then stating it in his July Poland speech but with a because-you-made-me sense. For all his ‘I like [Chinese President] Xi Jinping’ claims, it is not hard to see a shift back to China-bashing. His moderation on Israel may only be temporary, and based upon tactical calculations. If he does revert to more extreme positions on such issues, it will be a test for just how constraining public opinion is. (Other factors of course also enter in, and I am not claiming full causality one way or the other for public opinion).
But the most interesting issue is the overall America First one. The President is actually correct that the post-World War II/Cold War model—which, whatever their other differences, American hegemony, liberal internationalism, and neo-conservatism all embrace—no longer fits the twenty-first century world. The ‘grand strategy’ challenge is to come up with an alternative that is both substantively sound and can resonate with the American public.