Trump just put U.S. money where his mouth is.

On Thursday, the State Department announced that most U.S. security aid to Pakistan will be suspended until that nation "takes decisive action" against terrorist groups on its soil.

This is a big moment.

The Pakistani government has hinted that any U.S. aid suspensions would lead to a dramatic reduction in their counter-terrorism cooperation. Considering the scale of terrorist concerns emanating from Pakistan, that's no small threat.

Still, I have sympathy for Trump's action.

The simple truth is that Pakistan has too long enabled terrorists to endanger U.S. security interests and those of our allies in Afghanistan and India. This aid suspension sends the message: "We're serious, enough is enough." It will also help foster the vitally important U.S.-India strategic relationship and send a powerful message to the Afghan government that Trump won't let that nation collapse back into Taliban hands.

Indeed, India and Afghanistan now offer two textbook examples of how the Trump administration is supporting important U.S. allies rather than, as is the frequent media refrain, abandoning them.

Second, for all its many flaws, the Pakistani government is relatively stable. The risks that this aid suspension could lead it to collapse into extremist hands are low. The most obvious short-term consequence will be a jockeying match between Pakistani politicians as they seek to show their anti-American stripes in the run-up to July parliamentary elections. But that was inevitable even before this aid decision.

I have one caveat, however.

As I noted earlier this week, the Trump administration should keep open lines of cooperation with the Pakistani army. Absent that ground force commitment against terrorists, the ability of groups like al Qaeda to retain logistical safe havens will be advanced.

Ultimately, the objective of this aid suspension should be to pressure Pakistan to fundamentally reconsider its approach towards Islamic extremist groups. But if he can fuel the ongoing Pakistani internal debate as to where its interests lie, Trump will have won a legacy foreign policy accomplishment.