By introducing new sanctions on China over its purchase of Russian military equipment, the Trump administration hit a double against America's two major adversaries.

But with the sanctions also targeting 33 Russian military-intelligence officers, the Kremlin is predictably upset. Its foreign ministry claims that the U.S. is "playing with fire." But we should ignore these complaints. After all, Russian President Vladimir Putin's rampant use of nerve agents on British soil, his continued support for Bashar Assad's slaughter, and his assault on Western democratic security all justify this U.S. constriction of his key growth export market: military arms.

In that context, the U.S. sends a very powerful signal to other Russian arms importers, such as Egypt and India, with its sanctions against China. They should reconsider future purchases. This kind of action represents an important challenge to Putin's global strategy.

Of course, these sanctions are also a challenge to China. Considering China's aggressive military posture in the South China Sea and its efforts to displace the U.S.-led global democratic order, it is crucial that the U.S. counter China across the board of its power portfolio. Though unlikely to stop China from buying Russian military equipment, this action lets President Xi Jinping know that the U.S. isn't going to waiver in face of his challenge. And that speaks to a broader reality when it comes to the U.S. policy approach towards Beijing: strength.

I don't believe that the U.S. should try to compete with China in the low-value goods market, but Trump is constraining Beijing in a way it has not seen for a generation. Beijing's economic slowdown, and the fact that Chinese exports to the U.S. are far more easily offset than vice versa, the U.S. has means — some yet to be utilized — to extract significant concessions from China in the ongoing trade showdown.

In short, Trump has done a good job here.