France this week got tougher on Iran, sanctioning Iranian assets and raiding an Iranian intelligence-linked Muslim center.

The primary motivation for French action here is Iran's failed plot this summer to blow up delegates at a conference just outside Paris. Hosted by a group that seeks the overthrow of the Islamic revolutionaries in Tehran, that conference was attended by Rudy Giuliani. Allied intelligence services detected the plot and linked it to an Iranian intelligence officer operating out of Iran's embassy in Vienna, Austria. And on Tuesday, the French government directly blamed Iran's MOIS civilian intelligence service for orchestrating the failed attack. Simultaneously, French authorities also conducted a raid against an Iranian-supported front organization in northern France.

But why, specifically, is France upping the ante against Iran?

Primarily, because France recognizes that Iran is laying the groundwork for new terrorist attacks in Europe. It has become increasingly clear in recent weeks that the MOIS, the Iranian revolutionary guards Quds force, and its proxy the Lebanese Hezbollah are building capacity to conduct terrorist attacks if Tehran orders such action. Still, that development is not particularly surprising. After all, with U.S. sanctions on Iran's oil exports coming in November, Tehran believes a showdown with America is increasingly likely. It is proving as much in its actions. And while President Macron opposes U.S. sanctions on Tehran and is actively working with his European Union partner to defeat those sanctions, Iran has no qualms about carrying out attacks on western soil.

France knows this. But it also knows that Iran knows that France's highly competent foreign and domestic intelligence services; the DGSE and DGSI, are a force to be reckoned with. In turn, these latest French raids and indictments are designed to deter Iran from taking action on French soil. The French want the Iranians to know that they are being watched. Evidencing as much, a French government statement on Tuesday noted that France blames the "Internal Security Department of the Iranian Ministry of Intelligence" for the June plot. That precise blame on a specific department of the MOIS is designed to tell Tehran: "We know more about what you are doing than you think we know. Proceed with caution."

It's a powerful message because while France prefers peaceful cooperation with Tehran, French officials also know that Tehran knows they are capable of taking aggressive action. It is important to note, for example, that France participated in the last round of airstrikes against Iran's close ally, Bashar Assad, after he again used chemical weapons against his people. The French DGSE also cooperate closely with the CIA, the British SIS, and the Israeli Mossad in monitoring Iranian activities in Europe and the Middle East.

Put simply, this week's actions are a credible French warning shot off Iran's bow.