Having invaded Georgia and Ukraine, Moscow now periodically threatens our NATO allies with nuclear attack. It reinforces these threats with “practice” military exercises and adds new types of nuclear weapons into its stockpile.

Small wonder then, that the meeting in Helsinki between President Trump and Russian President Vladimir Putingenerated so much interest over the last week. Would it yield a breakthrough or just a photo-op? A love fest or fist fight?

Here’s are some key questions that may help you decide whether the meeting was a hit or a miss on nukes and missile defense.

1. Did Mr. Trump let Mr. Putin know that the U.S. won’t be extending the New START arms reduction treaty beyond its 2021 expiration date?

In hammering out the treaty, U.S. negotiators assumed relations between the two countries would be, at worst, benign. Consequently, they made a deal in which most of the reductions applied only to U.S. nukes. One-sided as it was, Russia has still, at times, built up its nuclear arsenal above the treaty ceilings. Moreover, the treaty is not effectively verifiable.

Extending New START would not contribute to “strategic stability,” because Russia is not interested in such stability. Its massive nuclear weapons modernization program and advantage in short-range nuclear weapons tell us as much.

Letting the treaty expire would strengthen U.S. negotiating leverage in the long run. Future negotiators can include Russia’s new nuclear weapons, such as those specifically designed to attack U.S. coastal areas. They can set U.S. nuclear weapon numbers based on Russia’s demonstrated, continuing antagonism rather than on wishful thinking about Moscow “softening” if the U.S. makes just one more concession.

For its part, Moscow is likely to be interested in future negotiations on strategic systems. Russia’s leadership has always been attracted to summit diplomacy. Moscow sees it as an affirmation of its great power status, despite Russia’s poor economic performance, conventional military inferiority, and negative demographic trends.

The U.S. is finally beginning its own nuclear weapons modernization program, making it more likely that Russia will seek arms control as a way to gain insights into such efforts, for example via on-site inspections that have become a standard of arms control agreements.

2. Did Mr. Trump raise the issue of Moscow’s continuing non-compliance with other pacts, such as the Intermediate-Range Nuclear Forces (INF) Treaty and the Chemical Weapons Convention?

New START defenders don’t want Mr. Trump to link Russia’s violations of other arms control agreements to the future of New START. But extending New START while countenancing these violations would indicate to Mr. Putin, and others, that we do not particularly value whether countries abide by their international obligations.

Russia’s INF violations are concerning because they are intended to drive a wedge between Washington and its NATO allies. This makes this treaty another excellent candidate for the scrapheap. What’s the point of having a treaty that only one party honors? For years, Russia has acted as if there were no INF Treaty whatsoever.

3. And possibly most important, did Mr. Trump give any indication that he might accede to Mr. Putin’s desire for the U.S. to limit or scrap its missile defense programs?

There is no doubt that Mr. Putin wishes to deny the West a strong missile defense. Cooperation on missile defense among the U.S. and its European allies has been a thorn in the Russian bear’s side since its inception.

But the proliferation of ballistic missiles — from the Middle East to North Korea — makes advancement of the U.S. missile defense program and continued cooperation with our allies a strategic imperative. Should we not intercept a missile en route toward its victims just because its launch point was somewhere in Russia?

Summits can serve U.S. interests. We can use them to counter Russia’s propaganda or to find areas of mutual interest and potential cooperation. But placating an adversarial regime to come to a pretense of an agreement is not it.