Donald J. Trump has made precisely the right call in canceling a planned meeting in Argentina with Russian tyrant Vladimir Putin.

It wasn’t the Russian attack on our electoral system in 2016 that produced the abrupt cancellation. Nor was it Russia’s alliance with Syrian dictator Bashar al Assad in his civil war with insurgents.

The cancellation comes after Russian ships collided with Ukrainian ships and took Ukrainian sailors captive in the Black Sea. The president said the aggression cannot stand.

He had planned to meet with Putin one-on-one during the G20 meeting in Argentina. That’s now off.

I won’t speculate on the impact of all the other “Russia things” that might be hanging over the heads of both men. Nor will I wonder whether the president didn’t want to risk a repeat of that hideous summit in Helsinki where Trump sided with Putin’s denials on Russian interference in our elections, dismissing the findings of the U.S. intelligence community that, yes, they most certainly did interfere.

I’ll simply say the president need not meet with Vladimir Putin until the Russian strongman makes amends for his latest act of aggression. Accordingly, Donald Trump made the right decision.