Nebraskans have long appreciated the need to balance a strong national defense with firm diplomacy. Unfortunately, a weakened defense posture and erratic diplomatic efforts are thwarting our ability to promote peace and protect our national interests around the world.

On July 28, the Obama administration officially declared Russia to be in violation of the Intermediate-Range Nuclear Forces (INF) Treaty. The 1987 treaty outlawed the testing, production and deployment of intermediate-range, ground-based ballistic and cruise missiles. Under the treaty’s terms, over 2,600 U.S. and Russian weapons — capable of carrying thousands of nuclear warheads — were dismantled.

Russia’s violation of this treaty is no small matter.

Doubts about Russia’s treaty compliance began in 2008. Since that time, Congress has pushed the administration to act, an effort I joined as a U.S. senator.

While new cruise missiles may not represent direct threats to American cities, they do threaten our allies and service members based overseas. We are obligated to defend our NATO allies, which is why weapons built to attack them deserve our urgent attention.

Russia’s blatant disregard of international law is not an isolated incident. A pattern of troubling Russian aggression is emerging, perhaps most clearly demonstrated by Vladimir Putin’s annexation of the Crimean Peninsula. Russia is interested in more territory, not the moral high ground.

Combined with its brazen support of separatist forces responsible for shooting down a commercial airliner filled with nearly 300 innocent passengers, the Putin regime’s actions make clear it does not share the desire for peace and stability that unites the civilized world.

Recent events have reinforced the wisdom of President Ronald Reagan’s famous mantras of “peace through strength” and “trust but verify.” These weren’t just slogans; they were the pillars of a focused foreign policy.

I believe the world could use a little more clarity — and a lot more leadership — from the United States.

As a first step, we should make clear that further reductions in nuclear forces are not possible until Russia’s violation has been addressed and its compliance with the INF Treaty can be verified. When the president first announced his desire to reduce up to one-third of our nuclear forces in Berlin last year, I argued in a Politico opinion piece that the unmet challenge of modernizing our nuclear forces should be prioritized above reductions.

Nebraskans uniquely understand the importance of maintaining and modernizing our nuclear deterrent. Each day, some of our friends, family members and neighbors head to work at the U.S. Strategic Command, where they help perform a vital deterrence mission with equipment that has been pushed far beyond its designed lifetime. It is well maintained and effective, but systems dating back to the 1960s aren’t going to last forever.

As our nuclear deterrent ages, our adversaries are developing modern, highly capable nuclear weapons systems. Indeed, Russia is willing to violate its treaty obligations to acquire new strike capabilities, suggesting these weapons are of great importance to their national ambitions. To paraphrase Margaret Thatcher, this is no time for the United States to go wobbly.

While the INF Treaty bans building or using intermediate range weapons, nations are permitted to research them. I believe this is an option our government should explore. By signaling our intent to prevent Russia from gaining a significant military advantage, we may be able to convince Putin to halt his behavior and comply with INF Treaty obligations.

In a 2013 New York Times opinion piece, Putin expressed his supposedly unwavering commitment to international law and disparaged the idea of American exceptionalism. The world has seen the truth of his views on international law; we should reinforce to him the truth of American exceptionalism. We take our treaty obligations seriously.

We need to take violations of these obligations just as seriously. As President Barack Obama stated in his 2009 speech on nuclear arms control, “Rules must be binding. Violations must be punished. Words must mean something.”

I couldn’t agree more.

Unanswered treaty violations suggest weakness; weakness invites aggression. The world is a safer place with American leadership.

To lead, though, we must have a full arsenal of diplomatic and military tools — including a modern nuclear deterrent — to counter those who wish to dim the bright light of freedom here and around the world.

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