The proper path would have been to create a new treaty outlining a new purpose for the alliance, not just to keep the club together. The EU, including its U.S. Ambassador, was already present in Europe, and some in the EU also had a military alliance created by the Treaty of Rome. Multiple layers of government doing the same tasks is nothing more than bureaucracy.

So, that 1998 letter came to mind recently after hearing members of the media and self-appointed policy experts blanching at the Republican presidential nominee’s suggestion that NATO might be obsolete in its current composition, and that its 28 member nations should meet their commitments of two percent of GDP for defense spending.

The response from Beltway opinion was bemusement, along with claims that this was the “first mainstream presidential candidate to ever suggest that the United States withdraw from NATO,” though that’s a rather obvious distortion of what Mr. Trump said. More recently, President Obama called Mr. Trump’s views on NATO “an indication of the lack of preparedness that he has been displaying when it comes to foreign policy,” without a hint of irony.

When Mr. Trump suggested earlier that he thought he “could get along well with Vladimir Putin,” many in the establishment media and even a number of our fellow Republicans took issue with the statement — as if it is an imperative that any presumptive president should reflexively denounce the Russian president, even when he could very well end up as a necessary partner in regional conflicts. As an email scandal has erupted at the opening of the Democratic National Convention, the official Democrat response has been to place the blame directly on Moscow.

Mr. Trump’s notably more diplomatic response reminded me of one of the 1998 letter’s more prescient lines: “we seem to take rather cavalierly the opportunity at long last to build a friendship with Russia.” There was a brief window after 1991 when the former Soviet Union opened up to the West. William Perry, who was President Clinton’s Defense Secretary from 1994 to 1997, recently recounted this opening during a speech in London: “In the last few years, most of the blame can be pointed at the actions that Putin has taken. But in the early years I have to say that the United States deserves much of the blame. Our first action that really set us off in a bad direction was when Nato started to expand, bringing in eastern European nations, some of them bordering Russia.”

At that time, America’s standard strategy of “forward defense” was already being displaced by the use of smaller, more nimble forces. NATO itself had long recognized the need to adjust to a changing threat matrix, reducing U.S. forces in Europe by two-thirds between 1992 and 1994 and establishing a Rapid Reaction Force to provide more flexibility.

More recently, the threat has shifted again, making it necessary to focus on counterterrorism worldwide, as Radical Islamic terrorism and the threat of its insertion into uncontrolled migration flows across open borders becomes a greater threat to most NATO countries than Russia. On ABC’s This Week back in March, Mr. Trump acknowledged this new threat: “we should readjust NATO. And it’s going to have to be either readjusted to take care of terrorism or we’re going to have to set up a new — a new coalition, a new group of countries to handle terrorism.” Not long after, NATO announced a new Assistant Secretary General for Intelligence who would focus on intelligence and counterterrorism.

More recently, when answering a question about whether the U.S. would respond if Russia attacked one of the smaller NATO allies like Estonia or Latvia, Mr. Trump said, “If they fulfill their obligations to us, the answer is ‘yes.’” President Obama demurred, saying, “There is a big difference between challenging our European allies to keep up their defense spending, particularly at a time when Russia’s been more aggressive, and saying to them, ‘You know what? We might not abide by the central tenant of the most important alliance in the history of the world.'”

Yet “challenging” NATO allies to pay their contractually-obligated 2 percent of GDP for defense has thus far failed, as only five of the 28 member countries are currently meeting that obligation. But the vastly more perilous side of the contractual-obligation — putting NATO members’ troops in harm’s way — is expected to be followed without question.

But this is also not a new problem with our NATO partners. Back in 1984, we passed legislation which, “Mandate[d] repayment of NATO debt before certain further U.S. appropriations would be freed.”  NATO owed U.S. government over $250 million in back payments even back then.

When my former colleagues and I came together to write that bipartisan letter back in 1998, we could see that NATO had the potential to become less of a bulwark than a tripwire if it continued its trajectory of ill-advised expansion. Our question was, “How can we admit some and exclude others without creating instability and tensions?” If the goal was stability in Europe, how, we asked, “can there be stability if Russia is destabilized by expansion?”

Today, I find that the reluctance to question the role of NATO in its current form is far more dangerous and short-sighted than a pragmatic proposal to reevaluate its efficacy in light of changing conditions. In his autobiographical “Waging Peace, 1956-1961: The White House Years,” President Eisenhower, noting his own concerns, expressed to JFK during his transition that, “America is carrying far more than her share of free world defense.” Mr. Trump’s suggestions that NATO’s members share its costs more equitably and that its doctrine be adjusted to focus more on terrorism, where the U.S. and Russia’s threat horizons converge, seems more realistic and wise in the light of history.

Former U.S. Senator Mack Mattingly served as a senator for from the state of Georgia 1981-87, and served as Assistant Secretary General for Defense Support NATO under President Ronald Reagan and President George H.W. Bush, from 1987-90. He served in the U.S.Air Force, 1951-55.