What makes NATO the most successful military alliance in history is the cohesion of its members. Any policy that risks undermining that should be examined with a highly critical eye.

Establishing a permanent U.S. military presence in Poland, as has been reportedly requested by the Polish government, is exactly one of those cases. Such a move should only be taken if consensus can be achieved among all our allies that it would enhance deterrence and improve the overall security situation for NATO.

That is unlikely to happen — and with good reason.

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To begin with, many of our allies would see the establishment of a U.S. military base in Poland — or anywhere else in Central or Eastern Europe — as unnecessarily provocative. It would give Moscow an easy opportunity to claim that NATO is an aggressor and to somehow respond to protect Russian sovereignty.

Unlike the current program of rotational forces, which cycle in and out over limited periods and then return to their home base in the U.S., a permanent base would require U.S. installations, families, schools, shops and all the other infrastructure that comes with it. Some would see this as a violation of the 1997 NATO-Russia Founding Act, the road map for security cooperation between the two entities. Moscow certainly would.

There are other ways to deter Russia than to build permanent bases. One is to to expand the use of rotational forces to all eastern flank nations — from Estonia down to Bulgaria as well as in Ukraine and Georgia.

I absolutely don’t believe it is a violation. The Russians blew that out of the water when they invaded Ukraine and changed the security environment envisioned at the time when the act was signed. But I don’t think it is wise to move ahead with a policy that would feed Russian fears, real or not. The move could also create additional friction with allies who are already at odds with each other over Washington’s withdrawal from the Iran nuclear deal and just-announced tariffs on steel and aluminium.

Second, a base in Eastern Europe is unnecessary. The current exercise and deployment program and other important measures — including the placement of equipment needed for armored brigades in pre-positioned stocks — are part of a robust effort to ensure an adequate deterrent against a possible Russian attack. NATO’s adaptation initiative, which is designed to provide the alliance with more flexible response capabilities, is expected to be adopted at the July NATO summit in Brussels and will further improve this effort.

The deployment of enhanced forward presence battlegroups into Estonia, Latvia, Lithuania, and Poland in early 2017, just months after the NATO summit in Warsaw, demonstrated real commitment to deterrence. The speed with which they were deployed showed NATO’s decisiveness, and their multinational makeup — including contributions from Italy, Spain and Croatia — reflect the alliance-wide commitment.

Particularly noteworthy was the decision by Germany to take responsibility as the framework nation for the battlegroup deployed to Lithuania. It was the first to do so and the first to deploy. This was a strong signal to Russia, as well as to other NATO allies. The return of Canada to the European continent, as a framework nation for the battlegroup in Latvia, was another strong strategic message of commitment.

Continued improvements to this deployment has strengthened its coherence and effectiveness. The Saber Strike 18 exercise, about to get underway in all four countries, with troops coming from Germany and the newly-arrived rotational armored brigade combat team from the U.S., will strengthen it further.

Third, from a practical standpoint, permanently placing an armored brigade combat team in Eastern Europe is simply unfeasible. It would require an expansion of the U.S. Army that does not appear likely to happen. Otherwise the Army would have to move one of the existing combat teams from their current home in Texas, Kansas or Colorado — a change that would encounter strong congressional resistance from those states’ delegations. And due to decisions made six years ago, there are no longer any armored brigade combat teams already based in Germany that could be repositioned further east.

Finally, the Army and therefore U.S. European Command, benefits from the increased readiness that comes from the use of rotational combat teams. A rotational team deploys from its home station via rail to Beaumont, Texas, travels by ship to a European port and then overlands again by rail or convoy to assembly areas in western Poland.

This is the exact process it would need to take in a real crisis, and thus invaluable practice for all of us, as we relearn what we used to know during the Cold War. Furthermore, this combat team will spend nine months constantly in the field or moving between training areas and across international boundaries, conducting more than twice as much gunnery as it would do in a typical 12-month training year back in the U.S. The benefits of working daily with NATO allies is also a significant training benefit.

Still, it’s fair to look at Warsaw’s proposal. Eastern allies believe that the presence of U.S. forces would significantly increase the deterrent effect, because they believe that Russia would never attack and risk a kinetic confrontation with U.S. forces and the possibility of Russians killing Americans.

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There are ways we can achieve this strategic effect without straining the cohesion of the alliance. The use of rotational forces should be expanded to include all of the eastern flank nations — from Estonia down to Bulgaria as well as in Ukraine and Georgia. What’s really needed in these countries are logisticians, air and missile defenders, and military police, as well as intelligence and communications experts.

Most of these are found in the Army Reserve and the Army National Guard. I would recommend increasing the logistics and transportation capabilities in Eastern Europe in order to increase speed of movement of responding or reinforcing NATO forces. Furthermore, I’d recommend putting air defense units into these countries to protect the critical infrastructure necessary for mission command and the deployment of reinforcements.

The National Guard has partnership programs with all of these Eastern European nations. So, there are built-in opportunities for increasing U.S. presence in all of them.

If Eastern Europe wants to enhance NATO’s deterrent effect, a potentially divisive military presence is not the right way to do it. Far better to protect the cohesion of the Alliance, while ensuring that trained and ready forces are ready to move in if necessary.

Ben Hodges, a retired lieutenant general in the U.S. Army, commanded United States Army Europe in 2014-17. He is the Pershing chair in strategic studies at the Center for European Policy Analysis. He writes here in a personal capacity.