Almost 11 years have passed since the terrorist attacks of September 11, 2001. Those events catalyzed a series of global military actions by the United States, which led to an international social movement opposing these actions, especially against the wars in Afghanistan and Iraq. Given that the antiwar movement has existed largely in abeyance since 2009, enough time has passed to begin to reflect on the policy, political, and social effects of this movement.
Our baseline expectations for the policy effects of the antiwar movement ought to be low. In general, antiwar movements tend to be less successful in achieving their goals than other social movements because they challenge the security interests of state actors and, thus, receive relatively little facilitation from the state. As a result, antiwar movements rarely prevent nations from going to war, though, under the right conditions, they have the potential to significantly influence public opinion and weaken the institutional support for war. However, the challenges faced by antiwar activists were especially difficult in opposing the wars in Afghanistan and Iraq. The war in Afghanistan began with little public dissent. President George W. Bush had made definitive war plans for Iraq by July 2002, before the antiwar movement had begun in earnest. Once the Iraq War began, the Bush Administration demonstrated a willingness to pay immense domestic political costs to continue the war. In contrast, the antiwar movement had few financial resources and ran on a shoestring budget.
In line with expectations, the international antiwar movement appears to have had, at best, a slight effect on public policy. A reasonable argument can be made that a well-organized antiwar movement in Spain contributed to the Socialist Party’s success in the 2004 parliamentary elections, which ultimately led to Spain’s withdrawal from the “Coalition of the Willing.” Yet, there does not appear to be another country that undertook a major alteration in policy directly as a result of antiwar activism.
The antiwar movement did have important political effects in the United States. By 2006, the movement had weakened public support for the war, the Bush Administration, and the Republican Party, which was likely a contributing factor to the Democratic Party’s takeover of the US House and Senate in that year. However, it is difficult to disentangle the effect of the antiwar movement from the usual pattern of loss that the party of the president experiences during midterm elections, especially those held in the president’s second term. Nevertheless, the newly elected Democratic majorities never enacted any of the antiwar legislation that they introduced, or made effective use of the power of the purse, in order to restrain President Bush’s war powers.
The antiwar movement helped Barack Obama to establish credibility as a genuine antiwar candidate in 2008 by creating the space for him to speak at a 2002 antiwar rally in Chicago when he was an Illinois state senator. As a result, the antiwar movement contributed to US Senator Barack Obama’s victory in the 2008 Democratic primary contest against Hillary Clinton, which paved the way to his election to the presidency. It is unclear, however, how President Obama’s policies in Iraq differed from those that would have been implemented by Clinton, who would probably would have defeated John McCain had she been the Democratic Party’s presidential nominee in 2008. Moreover, President Obama’s war policies are, at best, marginally different from those that might have been implemented by a President John McCain. In carrying forward the policies of President Bush, McCain would likely have drawn down US forces in Iraq at about the same rate as did Obama. McCain would probably have placed greater insistence on a residual military force in Iraq than did Obama. But it is not clear that McCain would have escalated the conflict in Afghanistan, as did Obama. Given the conflicting direction of these effects, the net difference from an Obama presidency – in terms of direct war policy effects – appears to be slight.
Obama’s election as president played an important role in demobilizing the antiwar movement after 2008. As a consequence, the movement has been in abeyance since at least 2009. Hardcore antiwar activists continue to protest, but they do so largely within the framework of other movements, such as Occupy Wall Street. A few thousand people protested NATO’s May meeting in Chicago, but this event was a small blip, caused by the opening of an opportunity, rather than a sign of broader resurgence in the movement.
Ironically, the limited policy impact of the antiwar movement likely resulted, in part, from its mostly peaceful, nonviolent, nondisruptive nature. Social movement activism during the age of the “social movement society” has made protest a normal, routine part of politics. Politicians are likely to ignore movement activity when they find it nonthreatening. President Bush, for example, dismissed the historic, internationally-coordinated protests of February 15, 2003 as a mere “focus group.” In contrast, during the Vietnam antiwar movement, violent clashes between police and demonstrators tended to move policy in the direction of whoever perpetuated the violence.
Of course, it is impossible to establish definitely the nonimpact of the antiwar movement on policy. Doing so requires the evaluation of counterfactual scenarios that cannot be tested empirically. For example, if there had been no antiwar movement at all – if nobody had protested the war policies of the Bush Administration – it is plausible to believe that the administration would have been emboldened to take more aggressive military actions, possibly invading Syria or Iran. Or, perhaps the Bush Administration would have had the confidence to pursue more ambitious conservative domestic policies. Personally, I am inclined to believe that the movement did have these types of restraining effects but, as a social scientist, it is impossible to demonstrate them convincingly.
To claim that the policy and political effects of the antiwar movement were limited is not to say that the movement was unimportant. Indeed, the social effects of the movement may have been its most lasting contribution. The antiwar movement exposed millions of people to their first experiences with activism, which will likely shape the way that many of them think of, and participate in, politics for the remainder of their lives. The movement provided critical opportunities for activists to learn about new tactics and to implement them on unfamiliar terrain. Alliances and conflicts within coalitions shaped the structure of the social networks of movement participants. The movement provided activists with opportunities to explore their identities and to create new organizations by hybridizing elements of intersecting social movements. In many ways, we have only begun to see the long-term consequences of a generation shaped by the antiwar movement.
 Manuel Jimenez, “Mobilizations against the Iraq War in Spain: Background, Participants and Electoral Implications,” South European Society and Politics, Vol. 12, No 3 (September 2007): 399-420.
 Michael T. Heaney and Fabio Rojas, “Partisans, Nonpartisans, and the Antiwar Movement in the United States,” American Politics Research, Vol. 35, No. 4 (July 2007): 431-464. Available at: http://www-personal.umich.edu/~mheaney/AntiwarMovement.pdf
 Michael T. Heaney, “The Partisan Politics of Antiwar Legislation in Congress, 2001-2011.”
The University of Chicago Legal Forum, Vol. 2011 (2011): 129-168. Available at: http://www-personal.umich.edu/~mheaney/AntiwarLegislation.pdf
 Michael T. Heaney and Fabio Rojas, “The Partisan Dynamics of Contention: Demobilization of the Antiwar Movement in the United States, 2007-2009.” Mobilization: An International Journal, Vol. 16, No. 1 (March 2001): 45-64. Available at: http://www-personal.umich.edu/~mheaney/Partisan_Dynamics_of_Contention.pdf
 McAdam, Doug, and Yang Su. 2002. “The War at Home: Antiwar Protests and Congressional Voting, 1965 to 1973.” American Sociological Review, Vol. 67, No. 5 (October 2002): 696-721.
 Fabio Rojas and Michael T. Heaney, “Antiwar Politics and Paths of Activist Participation on the Left,” Paper Presented at the 70th Annual Midwest Political Science Association Conference, April 12-15, 2012, Chicago, Illinois. Available at: http://www-personal.umich.edu/~mheaney/Antiwar_Activist_Paths.pdf
 Michael T. Heaney and Fabio Rojas, “The Place of Framing: Multiple Audiences and Antiwar
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 Michael T. Heaney and Fabio Rojas, “Coalition Dissolution, Mobilization, and Network
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 Kristin A. Goss and Michael T. Heaney, “Organizing Women as Women: Hybridity and Grassroots Collective Action in the 21st Century.” Perspectives on Politics, Vol. 8, No. 1 (March 2010): 27-52. Available at: http://www-personal.umich.edu/~mheaney/Womens_Collective_Action.pdf
 Michael T. Heaney and Fabio Rojas, “Hybrid Activism: Social Movement Mobilization in a Multi-Movement Environment,” Paper Presented at the 2011 Annual Meeting of the American Political Science Association, Seattle, Washington, September 1-4, 2011. Available at: http://www-personal.umich.edu/~mheaney/Hybrid_Politics.pdf