Historically, states pursued nuclear weapons under the protective assumption that deterrence begins once a program reaches maturity; that is, when nuclear devices are assembled, tested, or deployed. To some extent all nine nuclear weapon states achieved that level of deterrent threshold during their proliferation stages. Iran had not achieved such maturity. Furthermore, when looking at the region historically the Israeli attack on Iraq’s Osirak reactor in 1981 and the 2007 strike on Syria’s Al-Kibar site both hinted at a willingness on the Israelis’ part to act preemptively to stop regional proliferators.

But the scale and coordination of this most recent strike go further. It sends a global message that enrichment facilities themselves, when capable of being targeted and penetrated by American GBU-57 bombs, inherently means that once you are closing in on enrichment, your facilities are fair game. This will be the truest when referring to adversaries of the US and its alliance network. It remains to be seen what would take place if an ally of the US were to proliferate nuclear weapons in this modern era without its consent.

This shift has profound implications for the future of proliferation. Any adversarial state aspiring to build nuclear weapons will now face a new strategic prerequisite: it must first develop the defensive capability to withstand a preemptive strike before it can even hope to proliferate successfully. That means constructing extensive, deeply buried underground facilities, tunnel networks, and hardened bunkers. They must be capable of surviving the US military’s most sophisticated bunker-busting munitions. It also means investing in robust air defenses, redundancy, deception, and a level of operational secrecy that rivals the most advanced intelligence agencies in the world.

Not every state can afford this. Proliferation is already an expensive and politically risky endeavor. The need to develop advanced passive defenses only compounds those challenges. Most would-be proliferators simply will not have the financial or technical wherewithal to defend their nuclear infrastructure at such a level, especially in the early, vulnerable stages of enrichment.

Iran, of course, will likely try again. The Islamic Republic has proven resilient, adaptive, and committed to achieving strategic parity with its adversaries. Unless it develops an indigenous system of defenses that can shield its critical infrastructure from aerial bombardment, future attempts will likely meet the same fate as the current one. Even if Iran builds bunkers and tunnel systems deep enough to shield its centrifuges, it will still face challenges of concealment, resource constraints, and foreign intelligence penetration.

The broader lesson here is stark; the window of opportunity for slow, open, or vulnerable proliferation may be closing. In the post Iran–strike era, nuclear aspirants will have to prepare for war before they prepare for the bomb. The cost of entry into the nuclear club has just gone up, not only in material terms but in strategic risk. Any state hoping to proliferate must now assume it will be struck before it succeeds.

This may serve to slow the pace of proliferation, but it could also make it more dangerous. Proliferators who internalize the lessons of the Iran strike may respond with greater urgency, opacity, and desperation. They may forgo the traditional step-by-step approach in favor of crash programs hidden deep underground or even move toward asymmetric hedging strategies that involve acquiring key technologies without crossing visible red lines. In such an environment, the risk of miscalculation on all sides grows.

The strike on Iran may therefore reduce the number of proliferators in the long run. But for those that do try, the game has certainly changed. As Stephen Cimbala recently argued, the precedent set by the Midnight Hammer strike on Iran should not be viewed in isolation. It marks a return to kinetic counter-proliferation under conditions of rising global instability, where deterrence is increasingly challenged by uncertainty and misperception.

In parallel, Peter Huessy emphasizes that restoring deterrence requires more than just missile defense or military strikes; it demands clarity of will and credible commitment to prevent nuclear breakout by adversaries.

Together, their analyses suggest that the US-Israel strike was not just about denying Iran the bomb, but it was also about reestablishing the normative firebreak against nuclear proliferation. The broader message is unambiguous: in an era where deterrence is fraying, those who wish to proliferate must now calculate not only how to build a bomb, but also how to survive the storm that will precede it.

If Iran is the test case, the future of proliferation will be shaped as much by preemption as by prevention, and only those with the means to withstand a midnight hammer will have any chance at joining the nuclear club. From now on, the path to the bomb runs through the rubble of facilities like Natanz and Fordow, and only the most prepared will make it out the other side.

Aaron Holland is a PhD Student at the University of Nebraska-Lincoln and an analyst at the National Institute for Deterrence Studies. All views expressed are the author’s own.

How US and Israeli Attacks on Iran Will Reshape the Future of Nuclear Proliferation was originally published on Global Security Review.

Total NATO military expenditures for 2024 are estimated at $1.474.4 trillion. As Russia grows increasingly assertive, many on both sides of the Atlantic are wondering how NATO member-states will step up and contribute to the continent’s defense.

To withstand a Russian attack, NATO must plan for between 35 and 50 extra brigades of 3,000–7,000 troops each—adding 105,000–350,000 soldiers. Germany must contribute 3–5 extra brigades or 20,000–30,000 combat troops.

Protection from air attacks is a major German and Eastern European vulnerability. Former German Defense Minister and current President of the European Commission Ursula van der Leyen recently emphasized the need for Germany, under its new defense plans, to quadruple its air defenses. That includes Patriot missile batteries and shorter-range systems to protect bases, ports, and railway transportation systems.

Should Russia attack NATO, hundreds of thousands of troops, together with tanks, equipment, and ammunitions, will have to make their way to the eastern front through Germany. Preparations for war with Russia indicate that Poland, the Baltics, and other Eastern NATO allies are primary targets, but so is Germany. During the Cold War, Germany had 36 Patriot missile air defense units. The count is down to nine—after donating three to Ukraine. Berlin just ordered four Patriot missile units at a cost of 1.35 billion euros.

The United States spends about 3.5 percent of its gross domestic product (GDP) on defense, but the Congressional Budget Office projects that will fall to 2.5 percent by 2034. NATO member-states recently issued a joint communique that said, “We reaffirm that, in many cases, expenditure beyond 2 percent of GDP will be needed in order to remedy existing shortfalls and meet the requirements across all domains arising from a more contested security order.”

The Baltic states are adamant about the need for increased defense spending. Tuuli Duneton, Estonia’s Undersecretary for Defense Policy, praised the 23 NATO member-states who now meet the 2 percent spending target. She suggested raising the spending goal to 2.5 to 3 percent.

Pointing to NATO’s “capability gaps,” Lithuanian Defense Minister Laurynas Kasčiūna stated, “We’ll start to talk at least about 2.5 percent as a floor,” pointing to NATO’s “capability gaps.” He added, “When we analyze what the countries need to develop soon, for a decade maybe, it’s not even 2.5 percent. It’s not even 3 percent. It should be more if you want more air defense systems, if you want more long-range strike capabilities.”

NATO plans focus on logistics, troop movement, and cyber defenses in preparation for conflict with Russia. After NATO’s plans for the biggest defense upgrade in three decades were agreed upon last year, now is the moment of truth: the minimum defense requirements to meet these plans were sent to national governments, highlighting significant shortfalls in air defenses, long-range missiles, troop numbers, ammunition, logistics, and secure digital communications.

Fixing these shortfalls requires billions of euros in investment. By autumn 2025, NATO aims to set binding targets for members to ensure Europe’s defense. Achieving these targets may be difficult due to budgetary constraints and differing views on NATO’s stance towards Russia.

NATO’s effort to navigate a moment of clear and present danger is made more difficult by the Herculean task of rearming. Deep industrial reconstitution and technological evolution are both needed and taking place across all value chains in all defense tech investments, including space, cyber, drones, and the role of artificial intelligence on the battlefield. Despite its current state of political uncertainty, change-adverse politicians and populations must be convinced of the need for refocusing on defense.

Europe must face a Kulturkampf in which Europeans overcome the three decades of cognitive denial about war in Europe. The biggest obstacle to the above efforts is likely to come from populations that are accustomed to generous welfare programs at the expense of defense preparations. Europe cannot tax its way out of its current problem. European taxes are already the highest in the world.

Compelling communication strategies are essential to justify the increased defense budgets. Officials need to emphasize the pan-European necessity for national and regional security. The twin brother of blood and treasure returned from a long hiatus. Making the argument to citizens becomes an even tougher sell if conscription across Europe is required to mobilize hundreds of thousands of troops to fight.

Asking ordinary citizens in Western or Southern Europe whether they are willing to die for Ukraine or Lithuania or even Poland will likely draw a negative response. Not all European populations seem willing, able, and ready to fight as nation-states united under the concept of pan-European patriotic defense. Those now leading the effort de guerre are found among Poles, Balts, and, in no small part, the newly energized Nordic countries.

In short, if Europe wishes to survive, it must adapt, deter, and defend itself now. Waiting will only add more blood and treasure to the bill that must be paid.

Christophe Bosquillon is a Senior Fellow at the National Institute for Deterrence Studies. He has over 30 years of international experience in general management, foreign direct investment, and private equity and fund management across various industries in Europe and the Pacific Basin. Views expressed in this article are the author’s own.

NATO’s Defense Math Does Not Add Up was originally published on Global Security Review.