After eight years of retreat from global leadership, American foreign policy is in shambles, with the country’s adversaries ascendant from Crimea to the Middle East to the Pacific. Abe Greenwald notes that among Barack Obama’s many foreign-policy misjudgments is his belief that Islamic State’s warriors “do no threaten our national existence.”

Can it be that the world’s most bloodthirsty opponents of human liberty—having gone from near nonexistence to virtual statehood in less than five years and having acquired chemical weapons and inspired or trained terrorists inside the United States—do not threaten our national existence? As a matter of our immediate reality, the answer is yes, Islamic State (IS) is not poised to topple the republic. But as a long-term matter, the answer is undoubtedly no: IS and its related groups, if not forcefully opposed, will threaten the United States as a whole.

This could happen in one of two ways. In one, small terrorist attacks will continue or even multiply in the United States. As . . . Americans (and other free peoples) acclimate to the new insecurity caused by further attacks, they will impose upon themselves ever more restrictions on their own freedom. . . .

In the other scenario, IS could begin carrying out spectacular terrorist attacks on U.S. soil. By spectacular, I mean something on the order of 9/11. This is not hard to envision, as IS already has the money, the manpower, and in some cases the advantage of American citizenship to facilitate a coordinated, high-casualty domestic attack. Should this come to pass, then we would inevitably be in an active state of war with another “country,” entailing all the sorrows and upheavals that come with it. Once again, the United States would suffer as a whole. . . .

National purpose is forged in response to a specific challenge—and, then, only when our political leaders recognize that the challenge is so great as to require the galvanization of the country. . . . The United States will reclaim its national purpose when the continued threat of Islamic terrorism becomes too great for another American president to ignore.

Early Friday morning, Israel attacked military installations near the Iranian cities of Isfahan and nearby Natanz, the latter being one of the hubs of the country’s nuclear program. Jerusalem is not taking credit for the attack, and none of the details are too certain, but it seems that the attack involved multiple drones, likely launched from within Iran, as well as one or more missiles fired from Syrian or Iraqi airspace. Strikes on Syrian radar systems shortly beforehand probably helped make the attack possible, and there were reportedly strikes on Iraq as well.

Iran itself is downplaying the attack, but the S-300 air-defense batteries in Isfahan appear to have been destroyed or damaged. This is a sophisticated Russian-made system positioned to protect the Natanz nuclear installation. In other words, Israel has demonstrated that Iran’s best technology can’t protect the country’s skies from the IDF. As Yossi Kuperwasser puts it, the attack, combined with the response to the assault on April 13,

clarified to the Iranians that whereas we [Israelis] are not as vulnerable as they thought, they are more vulnerable than they thought. They have difficulty hitting us, but we have no difficulty hitting them.

Nobody knows exactly how the operation was carried out. . . . It is good that a question mark hovers over . . . what exactly Israel did. Let’s keep them wondering. It is good for deniability and good for keeping the enemy uncertain.

The fact that we chose targets that were in the vicinity of a major nuclear facility but were linked to the Iranian missile and air forces was a good message. It communicated that we can reach other targets as well but, as we don’t want escalation, we chose targets nearby that were involved in the attack against Israel. I think it sends the message that if we want to, we can send a stronger message. Israel is not seeking escalation at the moment.