On Monday, President Trump set a new 10 to 12-day ultimatum for President Vladimir Putin to enter peace talks over Ukraine or face a new tariff regime intended to halt global sales of Russian energy products.

Trump is promising a 100 percent “secondary tariff” on any country that imports Russian energy products, targeting India, China, Turkey and others. He’s right to recognize that pressuring the Kremlin’s main cash cow is a way to grab Putin’s attention, but his approach is counterproductive and incomplete.

There are two ways to change Putin’s plans in Ukraine. The first is to stop Russia’s ability to wage its war of choice by constraining its finances. Oil and gas sales account for about a quarter of the Kremlin’s budget. The G7, including the U.S., has taken steps since the onset of the war to lower Russia’s energy revenues. Last month, the Kremlin’s tax proceeds from energy sales were at their lowest since........

© The Hill