Speaking at the United Nations General Assembly on Tuesday, President Trump issued a stark warning to Germany over its increasing reliance on Russian energy supplies: "Germany will become totally dependent on Russian energy if it does not immediately change course."

Here, Trump is referring to Germany's submission to the Russian-originated Nord Stream II pipeline. That pipeline, from Russia to Germany under the Baltic Sea, will provide natural gas supplies into western Europe. Yet by insulating Vladimir Putin's energy export economy and making Germany more dependent on Russia, Chancellor Angela Merkel and her successors will find less inclination to support tough measures against Russian aggression. Nor will Germany be inclined to do more to live up to its responsibilities under NATO by spending at least 2 percent of GDP on defense. This is a stark reality that many European leaders refuse to accept, yet it cuts to the heart of western security in the 21st century.

Trump was also clear in noting that some European nations – Poland, especially – are challenging Russia's energy blackmail. Praising Poland for its increasing use of Norwegian oil as a substitute for Russian gas, Trump showed he understands that it takes more than fine words at international summits to assert one's independence from foreign energy-based extortion. It depends on the choice to invest against powerful adversaries.

As my colleague David Drucker highlights, Trump should have mentioned Russia's seizure of Crimea as an example of adversarial conduct against sovereign nations. Still, the president's words on Russia's energy extortion strategy deserve praise.

Ultimately, the sharp distinction between Trump's words towards Germany and Poland were perfectly suited for the U.N. audience. After all, it is Germany that is casually regarded as the leader of the free world in the era of Trump. Yet measured where it matters most, Poland is the nation that is the better ally of western security. The U.N. deserved this wake up call.