Lots of pundits with expertise in foreign policy and the presidency have speculated about whether President Obama will send American combat troops back to Iraq in response to the recent military success of the radical Sunni group, Islamic State of Iraq and the Levant (ISIS). Last weekend, Obama announced that he will (for now) not send combat troops. Then last night, the administration said it will send “up to” 275 troops to help evacuate personnel from the US embassy in Baghdad. But if the Iraqi government’s position continues to weaken, I suspect there again will be debate about whether Obama will or should send significant numbers of actual American combat troops back into the country.

This follows past discussions of whether Obama should or would send troops to the Ukraine and to Syria, especially after the Syrian government crossed Obama’s “red line” by using chemical weapons. Here, I take no position on whether it is a good idea for the US to intervene with troops in these or future world hot spots. But I will make a prediction. Short of a new terrorist attack aided of a foreign government killing many US soldiers or civilians, Obama will not commit significant numbers of US combat troops to any new overseas war during his presidency. Not in Iraq. Not in Ukraine. Not in Syria. Not anywhere.

The reason is Obama’s partisan and ideological coalitions, which in the current era are essentially the same. Stretching back to the end of World War I, but especially after World War II, liberals were more supportive of international institutions like the UN, while conservatives prefered the U.S. to go it alone internationally. However, up though the 1950s and 1960s, liberal thinkers and leading politicians weren’t opposed to involving US ground troops in large wars overseas. It was Harry Truman (for his time, an economic and racial liberal) who initiated US involvement in Korea and Lyndon Johnson (again, an economic and racial liberal) who greatly escalated US involvement in Vietnam. But after the Vietnam War, American liberals changed their minds on ground troops in foreign wars. Unless there is a direct attack on the United States, American liberal writers, interest groups and politicians believe that sending substantial numbers of ground troops overseas is risky, ineffective, and often counterproductive.

Since the Nixon Administration, no Democratic president has ever sent (nor has any majority of congressional Democrats favored) substantial numbers of ground troops overseas on a new military mission except in direct response to an attack on US soil. Obama did support a temporary surge in the number of troops in Afghanistan, but for the purposes of paving the way for a later full pullout. Liberal Democrats in Congress criticized Ronald Reagan’s invasion of Grenada and George H.W. Bush’s invasion of Panama. A majority of Democrats voted against authorizing the first Gulf War and the second Gulf War. The only authorization of ground troops that Democrats have supported since Vietnam is the 2001 “Authorization for Use of Military Force,” which passed Congress almost unanimously just 3 days after the Sept 11 terrorist attacks.

There are ideological divisions among liberal Democrats over military matters. There is a more dovish and a less dovish wing of liberalism, but even the less dovish wing is very skeptical of deploying ground troops. And Obama is not from the less dovish wing. As Matt Yglesias pointed out last week, the main ideological division between Obama and Hillary Clinton in the nomination battle in 2008 was over foreign policy. Clinton sided with the less dovish wing of current liberalism. But even the Clintons and the wing of the Party they often represent are deeply skeptical of committing ground combat troops to new missions. Shortly after taking office, Bill Clinton withdrew US troops from Somalia. Clinton used air power in periodic airstrikes against Iraq to enforce a UN inspection regime, and conducted a NATO-approved bombing campaign in Kosovo that was very carefully designed to include no ground troops and result in zero combat deaths.

In the early and mid-2000s, there was a debate among liberal Democrats over how to respond to George W. Bush’s aggressive foreign policy. But the biggest debate was over whether Senators should be disqualified from the Democratic presidential nomination for taking cover-your-butt votes in favor of Bush’s Iraq war before recanting later, as well as (especially in the 2008 primaries) whether the US should directly negotiate with states like Iran and North Korea.[1] Democrats in Congress are divided between the more dovish faction and the less dovish faction. In the 2004 presidential primaries, John Kerry, at the time representing the less dovish faction, prevailed over the more dovish Howard Dean. In 2008, the result was reversed, when the more dovish Obama defeated the less dovish Hillary Clinton. But these factions are not very far apart, as shown by the fact that Obama invited Hillary Clinton to be his Secretary of State. Both sides are deeply skeptical and cautious when it comes to ground troops. Whatever their votes on congressional war authorization, it seems highly unlikely that, if Hillary Clinton or John Kerry were president in the 2000s, they would have invaded Iraq.

We had a test of the viability of the pre-Vietnam liberal perspective on overseas combat troops in Joe Lieberman, who ran for president in 2004 on an unapologetically pro-Iraq War platform. He had essentially no success, coming in fifth in New Hampshire, the only state he seriously campaigned in. There is hardly any public opinion or interest group constituency in the Democratic Party for that older form of liberal foreign policy.

In this polarized era, where Republican House members and senators being defeated in primaries is commonplace, Joe Lieberman’s is the only major Democratic figure from Capitol Hill to lose a primary. That happened because political novice Ned Lamont ran a successful 2006 primary campaign against him that focused mainly on Lieberman’s support for President Bush’s invasion of Iraq.

Obama has (perhaps surprisingly) continued some of George W. Bush’s military policies. Despite his campaign pledge to do so, he has failed to close the military prison at Guantanamo Bay. He has also aggressively pursued overseas drone strikes, even against American citizens. And NSA domestic surveillance has continued with no apparent interruption. However, his opposition to overseas troop deployments is probably the biggest difference between Obama’s military policy and his predecessor’s. He withdrew all troops from Iraq by 2011, ensuring that it was completed before the 2012 election. And he is reducing the number of troops in Afghanistan with a goal of having all troops out by the beginning of 2016, before the next presidential election.

Obama is part if an ideological and partisan coalition that is very skeptical of sending US troops to fight overseas wars. He has repeatedly affiliated himself with the more dovish wing of this coalition, especially its views on combat troops overseas. Any new commitment of troops is highly unlikely because Obama’s ideology and past efforts all point in the opposite direction.

[1] By “cover-your-butt votes,” I refer to the phenomenon that John Zaller observed in his chapter, “Strategic Politicians, Public Opinion, and the Gulf Crisis,” here (although I deserve all the blame for the label). He observes that members of the opposition party in Congress will often vote for authorizing a president to use force because it maximizes their flexibility later. They will still benefit politically if the president’s military operation fails, but are much less vulnerable to attacks if it succeeds. But if they vote no, they would still politically benefit the operation it fails, but be substantially hurt if it succeeds.

[Cross-posted at Mischiefs of Faction]