Having spent four years as supreme allied commander of the North Atlantic Treaty Organization, I have a fairly clear-eyed view of the alliance’s vast capabilities, and also a realistic sense of what it is willing to do. When President Donald Trump on Wednesday called for “NATO to become much more involved in the Middle East process,” there was some understandable mockery.

Nevertheless, it struck me as a sensible request — if an ironic one from a man who has repeatedly bashed the organization over recent years and called it obsolete.

Going ahead, there are two simple questions: What can NATO do operationally? And is it conceivable that the organization would greatly increase its presence in the most turbulent region in the world?

Let’s start with capability. There are 29 nations in the alliance, ranging from the American superpower to tiny Montenegro and its 1,950 active troops. While it’s correct to say that most of the European nations don’t meet the goal of spending 2% of their gross domestic products on defense, their collective outlay still amounts to the second-largest defense budget in the world behind the US. With roughly $300 billion allocated annually, the Europeans spend more than China (around $200 billion) and Russia ($70 billion) combined.

That spending buys some very capable kit, as the British would say. The Europeans have exceptional warships (including aircraft carriers and nuclear submarines); fifth-generation fighter aircraft (several countries are in the US joint strike fighter program); and highly competent ground troops, including top-shelf special forces. The military chain of command flows down from the very professional NATO headquarters in Mons, Belgium, where I worked with a staff of several thousand people from every nation in the alliance. NATO has other significant headquarters and bases in the UK, Germany, Italy, the Netherlands and elsewhere.

Equally important to the equipment is the experience the nations of the alliance have amassed: In the long wars in Afghanistan (150,000 NATO troops overall at peak); Iraq (many member-states deployed troops, and NATO overall still has a training mission); Libya (tens of thousands of airstrikes and a full-on naval blockade); the Balkans (tens of thousands of troops and peacekeepers over the past couple of decades); and on piracy missions. Collectively, hundreds of thousands of European military professionals have significant experience in the Middle East on land, at sea and in the air.

So what could the alliance actually do? Using its marine power, for example, NATO could form a Standing Naval Force Middle East, modeled on existing warship squadrons for the Atlantic Ocean and the Mediterranean Sea. In terms of aircraft, NATO could deploy several fighter squadrons on a rotating basis at Al Udeid Airbase in Qatar. NATO also has its own airborne command-and-control aircraft, as well as AGS long-dwell drones (a variant on the US Air Force’s Global Hawk) based at Sigonella on Sicily. My current successor as supreme commander, Air Force General Tod Walters, has standing concentrations of ground troops at his disposal that could supplement US forces. And NATO has advanced cyberwarfare capabilities.

Deterrence and military operational prowess rest on two things, however: capability and credibility. NATO’s capability is clear. The question is about the alliance’s political center of gravity. Shipping more troops out of Europe and into a dangerous neighborhood will not be popular, and Trump’s past criticisms of the alliance won’t help when it comes to changing minds. Most important, perhaps: There doesn’t seem to be a coherent strategy for the Europeans to support, beyond the president’s vague call that they get “more involved.” So what’s possible?

Initially, a maritime deployment is most practical and likely. Something along the lines of a six-ship group composed of frigates and destroyers, under the command of a one-star admiral, could be an effective counter to potential Iranian attacks on merchant shipping. The other logical step would be ramping up the existing NATO training mission, which is focused on building counterterrorism capabilities among the regional allies and partners. (This assumes, of course, that the Iraqi government will allow NATO troops to remain.)

At the more risky — and therefore less likely — end of the spectrum would be a NATO special-forces deployment against the remnants of the self-proclaimed ISIS along the Iraq-Syria border. Another possibility is stepped-up cooperation with the US in cyber-operations countering Iran, conducted from the NATO cybersecurity center in Tallinn, Estonia.

All of this would require the US to make formal, well-structured requests to the North Atlantic Treaty Council in Brussels, a body I have briefed countless times. There would be skeptical faces around that table of distinguished ambassadors. Many would feel, much as Trump has said, that it is time to depart “the blood-stained sands of the Middle East.” Most of the Europeans are far more concerned about deterring Russian activity in Europe than going “out of area,” in NATO parlance.

There are some practical and palatable options that the US might be able to push across the political barriers the White House itself has raised through its constant criticisms of the European partners. But expect plenty of skepticism. In war as in politics, you reap what you sow.

Bloomberg