Could a strong statement from McConnell check Trump’s threat to GOP, national security?

A Republican leader — we’re thinking Senate Majority Leader Mitch McConnell — should step up and articulate a coherent GOP doctrine on national security and foreign policy. Because the party’s presidential nominee cannot.

McConnell got off to a good start last week when he told Politico that he disagrees “totally” with Trump’s assertion that the United States can pick and choose which NATO allies to defend. “NATO is the most important military alliance in world history,” said Kentucky’s senior senator. “I want to reassure our NATO allies that if any of them get attacked, we’ll be there to defend them.”

Only once in 67 years has the North Atlantic alliance invoked its mutual defense commitment to respond to an attack on one as an attack on all. That was less than 24 hours after the terrorist attacks of Sept. 11, 2001. Our NATO allies sent 40,000 troops to Afghanistan where 859 of them died. Tiny Denmark sent 9,500 personnel to help the United States root out the 9/11 perpetrators.

It’s no surprise then that other Republicans also denounced Trump’s suggestion that as president he would refuse to defend a NATO ally if he didn’t think the country was paying enough for its own defense. That Trump would so casually speak of discarding the alliance that won the Cold War is unnerving.

So is his long-distance bromance with Vladimir Putin. Trump has talked of lifting the sanctions that were imposed after Russia’s expansionist dictator took Ukraine’s Crimean Peninsula in 2014. And there’s speculation that Trump’s pro-Russian attitude stems not from his view of our national interest but from his business interests with Russian oligarchs.

Trump insisted he was joking when he suggested that Russia should hack his opponent Hillary Clinton’s emails. It’s hard to laugh, though, when a would-be commander-in-chief invites foreign espionage into a U.S. election.

Trump has espoused torture and ordering the military to kill the families of terrorists, both of which are classified as war crimes. Rather than even acknowledge, must less engage, the complexities of our times, especially in violence-torn Muslim regions, he resorts to bombast devoid of specifics or anything resembling informed policies.

In March, 121 Republicans who have worked in national security signed a letter, enumerating how “Trump’s own statements lead us to conclude that as president, he would use the authority of his office in ways that make America less safe, and which would diminish our standing in the world.” The experts said Trump “swings from isolationism to military adventurism within the space of one sentence.”

Trump’s lack of experience, coupled with unshakeable conceit, has so unnerved Republican foreign-policy hands that, Politico reports, Trump would have a hard time finding qualified Republicans willing to work in his administration. Politico also reports that Trump is costing Republicans what always has been one of their big strengths: national security.

While many individual Republicans have distanced themselves from Trump, he is the party’s standard bearer. Even if McConnell thinks Trump can’t win, the nominee’s prominence gives his pronouncements power, with our allies and adversaries.

We understand the party is fractured and chaotic. But the Senate’s unique role in international relations gives McConnell standing to reassure Americans and the world by articulating a Republican vision or doctrine that could serve as a check on Trump’s wild swings.

Doing so would be not so much a political tactic as an act of statesmanship, even patriotism. So, how about it?