Today’s NATO Summit in Wales, where the leaders of 28 European and North American countries, including the United States, will meet to address pressing security challenges, is arguably the most important in a generation.

Why? The wolves are at the door.

The NATO allies must find a way to deal successfully with both Russia’s muscle-flexing in Eastern Europe and the stability-storm in the Middle East created by the Islamic State (aka ISIS or ISIL).

First, Russia. Western policies of mostly punitive, targeted economic sanctions have failed to stop Russia from doubling down on its commitment to pro-Kremlin rebels fighting for independence in eastern Ukraine.

There’s little doubt that Moscow is providing materiel, personnel, intelligence and moral support to the insurgents, who may be turning the tide against Kiev’s beleaguered army.

Russian President Vladimir Putin has also reportedly ratcheted up the rhetoric by claiming in a phone call with a European official that Moscow could roll over Kiev in two weeks. (The Kremlin disputes this.)

There’s rumor of a cease-fire in the fight that has taken some 2,500 lives so far, but a cease-fire is just that: a temporary halt in hostilities — not a permanent peace.

The battle for the heart, soul and territory of Ukraine, a country that borders NATO frontline states, is far from over and the worst may be yet to come if Putin perceives (more) weakness.

That brings us to the Islamic State.

It would be hard to argue that the West has this continuing nightmare under control. From the beastly beheadings to the chilling crucifixions, ISIS isn’t only an affront to our humanity, it’s a marauding menace to our safety and security.

President Obama rightfully took it on the chin last week when he publicly admitted a — let’s just say — severe shortage of strategy for dealing with ISIS. Clearly, that’s not going to cut it considering the out-and-out evil we’re facing from this terrorist “army.”

News reports indicate that perhaps hundreds of Canadians, Americans and Brits and thousands of Europeans have joined ISIS or other violent Islamist groups in Syria and Iraq (countries that border NATO member Turkey).

At the moment, the Islamic State threat may seem to be “over there,” but NATO members are likely to see battle-hardened foreign fighters try to return home, radicalize others and/or pull off acts of terror.

Yeah: It’s a NATO problem.

While there seems to be — at best — half a strategy for dealing with this peril (e.g., supporting Kurdish peshmerga and Iraqi forces as well as limited U.S. air strikes), a NATO plan to contain/rollback ISIS is needed.

The alliance arguably hasn’t faced this varied level of insecurity since the end of the Cold War. It desperately needs bold, sustained leadership (meaning American leadership) to build comprehensive, all-in strategies for tackling these threats to our collective interests.

A failure to find meaningful, actionable ways — beyond rhetorical flourishes in well-polished political speeches — to deal with these growing challenges will mean a fumbled summit and darker days ahead.

 - Dr. Peter Brookes is a Heritage Foundation senior fellow and a former deputy assistant secretary of defense.