Russian President Vladimir Putin killed the chance of peace in Ukraine when he escalated Russia’s armed incursion into east Ukraine late last month.

Unless the United States and the European Union come up with an adequate response, the consequences could be dire.

The escalation started when the European Union was about to discuss the possibility of lifting some of its Russia sanctions and just in time to undermine the plans to hold a summit on efforts to end the fighting.

The timing of the escalation demonstrates that Mr. Putin is not interested in peace.

It also proves that his military campaign in Ukraine is more than just an effort to create a land link between Russia’s mainland and the Crimean Peninsula, which Russia annexed last year.

Mr. Putin is trying to undermine Ukraine’s democratically elected pro-Western government and Ukraine’s effort to join the European Union and NATO. He is also testing the resolve of the United States and its allies to oppose him in his quest for the breakup of the European Union, the demise of NATO, and an ensuing Russian expansion in Europe.

When people in Russia see the bodies of civilians in pools of blood on sidewalks filmed after a recent Russian rocket attack on Mariupol, most of them — those who get their news from state television — believe “commentators” who blame the Ukrainian army and allege that it was armed by the United States and its European allies. Mariupol is a strategic Ukrainian port city on the Sea of Azov near the Black Sea.

The irony is that not only is that allegation untrue but that neither the United States nor any of its European allies have summoned the courage to ship weapons to Ukraine, which has long been imploring them to do so.

Russia also has subjected Ukraine’s neighbors — Latvia, Lithuania, and Estonia — to military provocations such as flyovers of nearby airspace by Russia’s military aircraft. In addition, a week ago, the Russian foreign ministry accused Latvia of discrimination against its Russian-speaking population.

Accusations such as that — but against Ukraine — were common before Russia invaded first Crimea, then mainland Ukraine. Latvia may be Mr. Putin’s next target, because it has a considerably more sizable Russian-speaking population than Estonia and Lithuania, the other two of the three Baltic states.

Following the flareup of fighting in Ukraine last month, President Obama ruled out the military option but talked about the need to “ratchet up the pressure on Russia.” The European Union extended by six months the existing sanctions against Russian and pro-Russian separatist officials and announced its plans to expand existing economic sanctions against Russia.

That is not nearly enough because economic sanctions have continuously failed to deter Russia’s aggression. More than 5,100 people have been killed since the fighting started in April.

The Obama Administration should heed the advice of former national security adviser Zbigniew Brzezinski, who told U.S. lawmakers following the Russian escalation in Ukraine last month that Washington and its NATO allies should deploy troops to the Baltic states to deter Russia from taking control of those countries.

But it is even more important to arm the Ukrainians so they can check Mr. Putin’s aggression now — before the United States and its allies have to face off with him in Latvia, Estonia, or Lithuania once he takes over Ukraine. Unlike Ukraine, those three countries are NATO members, so aggression against any of them will be viewed as aggression against all NATO member countries, including the United States.

It is now clear that Mr. Putin is trying either to reassemble the Soviet empire or to simulate such an attempt convincingly enough to persuade his own people who — brainwashed by his propaganda — are cheering for him.

Stopping Mr. Putin in Ukraine is critical if we want to avoid the doomsday scenario of Russian and NATO troops clashing in Europe.

Mike Sigov, a former Russian journalist in Moscow, is a U.S. citizen and a staff writer for The Blade.

Contact Mike Sigov at: sigov@theblade.com, 419-724-6089, or on Twitter @mikesigovblade.

First Published February 1, 2015, 5:00 a.m.