Rich Lowry explains for National Review Online readers why President Obama’s response to the attack on a Malaysian jetliner over Ukraine falls short of the mark.

President Ronald Reagan famously implored the Soviets to “tear down this wall.” President Obama’s injunction is, “Investigate this crash.” Or as he put it rousingly in his statement on Ukraine from the South Lawn Monday, “I’ve sent teams; other countries have sent teams.” If transportation-disaster assistance specialists strike fear in Vladimir Putin, the Russian strongman is no doubt daunted by the Western response.

A fair, expeditious investigation of the crash is obviously preferable to the depredations of Putin’s minions, but is largely beside the point. This isn’t the disappearance of Amelia Earhart. There is no mystery. Forces controlled by Putin shot a civilian airliner out of the sky. End of story. Whether Ukrainian separatists or Russian personnel pulled the trigger is almost moot, since both are creatures of the Russian state.

The downing of Flight 17 is of a piece with Putin’s lawless aggression. Having already absorbed Crimea, he seeks to further dismember a European country for the offense of seeking to govern itself in keeping with its values and interests.

So far, he hasn’t paid enough of a concrete price, despite repeated warnings from President Obama. When they go unheeded, Obama simply makes new warnings. They have marked each step of Putin’s escalation, and never made a difference. What Teddy Roosevelt was to gunboat diplomacy, Barack Obama is to the ineffectual demand.