OPINION: Will US boots hit the ground in Syria?

Pressure on the White House to escalate the Syria/Iraq war has no doubt intensified post-Paris. Should Islamic State strike an American civilian target, President Barack Obama would be all but forced to 'do something more'. What might that 'something' look like, and what would be the consequences?

For an Obama already wary of deeper involvement in Syria/Iraq, a ramping up of the air campaign may be enough to tamp down the current post-Paris pressure. France may also find the short and sharp set of revenge attacks already underway enough for the near term, as Jordan did at the beginning of this year, after the horrific burning alive of one its pilots by Islamic State. Things could then settle back into a more routine fight.

However, if Islamic State were to strike against Americans, Obama would almost be required to escalate, and more of the same air strikes would not satisfy demands for vengeance. Such gestures would not have been sufficient a year ago if an attack had come, and certainly will not be sufficient in the midst of a presidential campaign. Any perceived lack of resolve would hand the Republicans a red, white and blue issue to take them through the next 12 months, and Hillary Clinton would be forced to break with the White House.

America's escalation could take only one form: American boots on the ground.

No one would call it an invasion, but that is what it would be, regardless of scale. The most likely paths into Syria would be through Jordan, and Turkey, if that government blessed it (but remember, Turkey refused to open its borders for the 2003 American invasion of Iraq), with a smaller American force entering from the northeast, across the Iraqi border.

The United States has notable infrastructure and a compliant host government in place in Jordan. In May of this year, thousands of soldiers took part in war games there, overseen by the American Army. The Jordanians themselves are already considering a militarised 'humanitarian corridor' into Syria that could easily morph into an invasion route. Since 2013, the United States has been growing its military presence in Jordan, to include strike aircraft, missile defenses and strategic planners, lots of planners, the infrastructure of war.

An attack against Islamic State from the south might also help isolate Damascus, for follow-on action against Assad. From a military point of view, Israel and the Golan Heights it controls provide neat protection on the invasion's left flank. Lastly, Jordanian involvement would help dress up the American invasion by giving it something of an Arab face.

Sending large numbers of troops into Syria from the northeast, via Iraq, would be risky, given Islamic State's strongholds there. Foreign fighters could also find their way across the Turkish border, right into the American flanks. Still, quietly moving modest numbers of airborne and special operations troops through Kurdish-held areas would be possible and necessary to attack Islamic State from a second front.

It would surprising to see any significant American escalation in Iraq proper, absent perhaps inside the Kurdish confederacy. Americans dying once again in the Iraqi desert would be a tough sell domestically, and the Iraqi government in Baghdad and its Iranian partners would be less than receptive to large numbers of American combat forces. Militarily dividing Islamic State into a Syrian force and an Iraqi force would accomplish much on its own anyway, without re-inserting American troops into the tar pit of Iraqi civil war. Cut off from Syria, Islamic State in Iraq would be weakened enough to be crushed separately, perhaps by the Kurds, perhaps by Iraqi-Iranian forces.

The problem, however, with all this testosterone-fueled chess playing is the identical one that bred Islamic State into existence in the first place. As the United States saw in Iraq, Libya, and Afghanistan, winning on the battlefield is the easy part.

Assuming Islamic State could be destroyed (a big assumption given its diffuse nature and political support among many Sunnis), and vengeance sated, what follows? Who will govern 'liberated' areas? Will Russia simply stand aside? How much land will the Kurds seize for themselves in northern Syria and how will Turkey react to that?

Syria is a wrecked wasteland, flooded with internally displaced persons. Who will pay for reconstruction, and why would anyone think it would work any better in Syria than it did in Iraq and Afghanistan? Syria would become the breeding group for Islamic State's successor, as Iraq beget Islamic State from al-Qaeda.

Scenarios that put boots on the ground in Syria/Iraq are easy to foresee, and the possible strategies are clear enough to speculate on. But how to deal with the aftermath is what really matters, and what is the plan for that?

Peter Van Buren, who served in the State Department for 24 years, is the author of 'We Meant Well: How I Helped Lose the Battle for the Hearts and Minds of the Iraqi People', a look at the waste and mismanagement of the Iraqi reconstruction. His latest book is 'Ghosts of Tom Joad: A Story of the #99 Percent'.