Jorge Benitez is the director of NATOSource and a senior fellow at the Atlantic Council. You can follow him on Twitter @NATOSource . The opinions expressed in this commentary are his.

(CNN) This week, Secretary of Defense Jim Mattis is meeting with NATO defense ministers. On May 25, President Donald Trump will attend his first NATO summit.

At these meetings, both men will communicate the urgency the new Trump administration is placing on greater defense spending from our allies.

Trump will not be satisfied with traditional excuses and will probably express his blunt message that NATO allies have been " very unfair to us.

Most of our European allies will not be able to meet their NATO commitments on defense spending, but they can help fund a key defense initiative that will save relations with the Trump administration and also strengthen security in Europe: a multinational deterrence initiative, or MDI.

After Russia seized Crimea and invaded eastern Ukraine, the Obama administration created the European Reassurance Initiative (ERI) to fund actions that would make further Russian aggression less likely.

The ERI paid for more NATO exercises, improved infrastructure to facilitate the deployment and training of NATO forces of new members, and kept some US military units in Europe that were scheduled to be withdrawn. For 2017, the funding was quadrupled to $3.4 billion and the name was changed to the European Deterrence Initiative (EDI).

But, Obama's EDI is a unilateral effort that places the defense burden almost exclusively on the US. The Obama administration only asked for European contributions after the fact and, even then, its efforts were mostly half-hearted.

But why would allies change their defense spending for Trump, when they ignored pleas from previous US leaders such as President Obama and Robert Gates ? Because this time the Europeans have something substantial to lose. Unless America's allies join in contributing to the MDI, the Trump administration will probably cut or eliminate EDI funding all together.

The loss of EDI funding will have profound geostrategic consequences in Europe. It will mean the withdrawal of US forces. Those would include, at least, the 3rd Brigade Combat Team (BCT) and other units such as some US F-15 warplanes and attack helicopters. It may even require the withdrawal of the US battalion in Poland.

Militarily, it will be a significant blow to the capabilities of US forces. Politically, it will be seen as evidence of Trump's abandonment of Europe and will have a devastating effect on America's allies. It will also serve as a dangerous encouragement for greater Russian provocations against NATO members.

America's allies need to offer something tangible to Trump, like the MDI, to prevent the loss of EDI funds for US forces in Europe.

They should begin by increasing their defense spending to fulfill their NATO commitments. But most allies have so far to go and it is such a domestically challenging issue that it is certain not even half of NATO members will meet this target -- this year or the next. While a good faith effort is necessary, it is not sufficient. The deteriorating security situation in Europe and the expectations of the Trump administration will demand more.

The new MDI provides more and it provides it now, right when Europe needs it. It is a solution that is small enough to be feasible and implemented this year. America's allies spend about $240 billion on defense each year. An extra $3.4 billion (less than 1.5%) from all 27 of them is not an unreasonable amount to strengthen deterrence. Yet it is an amount large enough to match the US investment and thus help convince the new President to rotate more US troops into Europe, rather than out of the continent.

America's European allies are already making valuable contributions to European security. Examples are the participation of about 5,000 allied troops in exercise ANAKONDA in Poland and the deployment of allied warships in the Black Sea. These steps have merit, but they are too few and for the most part uncoordinated. They should pool these activities together through the MDI and fund more of them to rise to the level of the US investment in the MDI.

Channeling the contributions of allies through the MDI rather than unilateral efforts will provide accountability for NATO's European pillar and make it easier for national leaders to overrule their finance ministers.

The Trump administration is a tectonic change in transatlantic relations. Business as usual will not work.

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If America's allies offer Mattis and Trump only pledges of support that go unfulfilled, they will provoke a US response that may cause historic damage to security in Europe. But if they act responsibly and join our investment in strengthening defense on their continent, they will help deter further Russian aggression and ensure America's continued role in keeping the peace.