As the last U.S.-Russia arms treaty expires, wars in Ukraine and Iran are eroding the very rules that kept nuclear dangers in check for decades.

Story Highlights

• Experts say Russia’s war in Ukraine weakened core nonproliferation norms.
• Ukraine’s 1994 disarmament-for-assurances deal looks broken after Crimea and the wider war.
• New START’s 2026 expiration leaves no treaty capping the biggest arsenals.
• The nuclear watchdog lost track of key information on Iran’s nuclear material in June 2026.

Ukraine War Strains the Nuclear Rulebook

The Belfer Center concludes the Ukraine war is a blow to the “System of Nuclear Abstinence,” which includes nonproliferation and arms control. Analysts warn that Russia’s nuclear threats during the conflict have likely undercut the credibility of the Non-Proliferation Treaty, the backbone of global nuclear restraint. When a major power rattles the nuclear saber to shield a land war, smaller states notice. That pressure feeds doubt about treaties and pushes countries to rethink how to protect themselves.

Ukraine gave up a massive inherited arsenal in 1994 for security assurances under the Budapest Memorandum. Russia’s seizure of Crimea in 2014, followed by the full-scale war, showed those assurances lacked teeth. That failure now serves as a cautionary tale. Leaders in risky regions can read the lesson this way: paper guarantees do not stop tanks. That is exactly the kind of security shock that past research links to interest in nuclear options, even if most states never cross that line.

Arms Control Gap as New START Expires

The New Strategic Arms Reduction Treaty, the last cap on U.S. and Russian long-range nukes, expired in February 2026 without a follow-on deal. For the first time in about five decades, no treaty constrains the two largest arsenals. That removes guardrails that helped steady crises and verify limits. Without clear caps and inspections, mistrust can grow faster. When great powers stop leading on restraint, others have fewer reasons to hold back. That weakens the norm against nuclear spread.

Some argue the treaty system has still held up because the number of nuclear-armed states has not grown in 25 years. That view misses the present danger. The immediate risk is not a tenth nuclear state tomorrow. The risk is a steady slide in trust, rules, and verification that makes future breakouts more likely when the next crisis hits. The Belfer assessment stresses this erosion now, while policymakers still have time to restore limits and rebuild confidence.

Iran’s Program and Fading Oversight

The International Atomic Energy Agency reported in June 2026 that it lost continuity of knowledge on Iran’s nuclear material and lacked the access needed to verify in the field, after Iran halted the Additional Protocol years earlier. That loss makes it harder to judge what Iran holds and where it sits. Some commentary also points to Iranian lawmakers threatening to quit the Non-Proliferation Treaty and revisit doctrine, reflecting a desire for stronger deterrence amid strikes and turmoil. Those signals raise the stakes for fast, verifiable steps.

Western governments cite a memorandum between the United States and Iran that lays out a timeline to downblend enriched uranium under agency oversight, aiming to slow the risk and restore checks. Former officials add that strikes degraded Iran’s capacity, arguing Tehran cannot race ahead. These claims, while hopeful, do not replace on-the-ground inspection. Until inspectors confirm stockpiles and sites, gaps in knowledge remain. Gaps invite doubt. Doubt drives hedging, and hedging feeds the spread risk everyone claims to oppose.

What Conservatives Should Watch Now

Washington faces a dual task: deter enemies and revive real verification. The United States should push Moscow to accept a practical cap-and-checks framework that protects American strength and transparency at the same time. The White House and Congress should tie any future relief for Iran to restored inspector access, clear downblending, and swift disclosure of hidden work, with snapback penalties if Tehran cheats. Transparency and leverage, not blank checks, are the only path to steady ground.

Americans who believe in peace through strength can back steps that secure our families and our allies. That means rebuilding a credible arms control floor that costs us nothing in deterrence but lowers the odds of miscalculation. It means ending the habit of trusting paper promises without enforcement. And it means calling out regimes that hide or threaten withdrawal from treaties. The lesson from Ukraine and Iran is simple: when rules fade, risks rise. It is time to restore both power and proof.

Sources:

theamericanconservative.com, belfercenter.org, grc.net, armscontrol.org