{"id":29380,"date":"2026-07-23T09:00:58","date_gmt":"2026-07-23T07:00:58","guid":{"rendered":"https:\/\/voelkerrechtsblog.org\/?p=29380"},"modified":"2026-07-24T20:45:21","modified_gmt":"2026-07-24T18:45:21","slug":"wind-of-nuclear-change","status":"publish","type":"post","link":"https:\/\/voelkerrechtsblog.org\/de\/wind-of-nuclear-change\/","title":{"rendered":"Wind of (Nuclear) Change"},"content":{"rendered":"

Under international law,\u00a0Germany is not as irrevocably barred from acquiring nuclear weapons as is commonly assumed. In certain circumstances, Germany could be released from Article 3 of the Treaty on the Final Settlement with Respect to Germany (known as the Two<\/u>\u00a0<\/u>Plus<\/u>\u00a0<\/u>Four <\/u>Agreement<\/u><\/a>, or 2+4) and withdraw from the Non-Proliferation Treaty<\/u><\/a> (NPT). This would allow Germany to pursue a nuclear weapons program without violating international law\u2014or\u00a0to trade that latitude for renewed, credible security guarantees. This understanding should be a prerequisite for any serious strategic debate.<\/p>\n

A caveat:\u00a0the argument is not<\/em> that Germany needs nuclear weapons. Germany should impartially assess which options are available and what they cost. The question this commentary takes up is the legal one; the political one is separate, and it cannot be answered on a false legal premise.<\/p>\n

The NPT Review Conference<\/strong><\/p>\n

The eleventh NPT Review Conference concluded on 22 May 2026.\u00a0Like the conferences of 2015 and 2022, it reached no consensus. In the closing\u00a0press conference<\/u><\/a>, its President, Do Hung Viet, recalled warning that a third inconclusive conference \u201cwould be disastrous for this regime\u201d\u2014by his account, the NPT community had not produced a shared commitment in sixteen years.<\/p>\n

Consensus on a final document failed\u00a0amid what the Arms Control Association reports<\/u><\/a> was\u00a0a dispute over blame for the\u00a0U.S.-Israel-Iran conflict\u2014though not the only issue; a draft provision strengthening review and accountability was also dropped. This failure has precedent: in 2022<\/u><\/a>, the primary obstacle was Russia\u2019s objection to language on its occupation of the Zaporizhzhia plant; in 2015<\/u><\/a>, the U.S. blocked a proposed conference on a Middle Eastern zone free of weapons of mass destruction.<\/p>\n

This failure deepens the rift in the nuclear order\u2014the structure governing relations between nuclear and non-nuclear states.\u00a0The moment thus provides an opportunity\u00a0to examine whether\u00a0the order, as it stands, remains the least bad option, or whether it should give way to something that achieves better security. Central to this is an understanding of the ban on German nuclear weapons.<\/p>\n

T<\/strong>he NPT<\/strong><\/p>\n

According to the NPT, there are nuclear-weapon states (NWS)\u2014the U.S., Russia, the U.K., France, and China\u2014and non-nuclear-weapon states (NNWS). India, Pakistan, Israel, and North Korea\u2014whose withdrawal status is disputed\u2014are not parties to the NPT but possess nuclear weapons. Article I prohibits NWS from transferring nuclear weapons to NNWS, making\u00a0nuclear sharing\u00a0legally contested; the wording arguably allows\u00a0for a \u201cdual-key procedure.\u201d\u00a0Article II prohibits NNWS from developing nuclear weapons, though peaceful nuclear energy is guaranteed (Article IV).\u00a0Article III governs inspections and verification. Article VI obligates parties to pursue disarmament \u201cin good faith.\u201d<\/p>\n

Under Article X, any party may withdraw if it perceives \u201cextraordinary events\u201d as a threat to its \u201csupreme interests.\u201d\u00a0It is therefore inaccurate to claim that the NPT permanently bars Germany from producing or possessing nuclear weapons. But since the NPT serves as the cornerstone of the nuclear order, publicly\u00a0considering\u00a0withdrawal could undermine that order.<\/p>\n

The U.S.-Israel-Iran conflict shows it is not only a matter of rights but of geopolitics: Iran, still a party, has faced military strikes, while North Korea\u2019s 2003 withdrawal brought only sanctions. Should Iran emerge without new treaty obligations and with the regime intact, it could follow North Korea\u2014and further U.S.-driven confrontations could draw South Korea, Japan, or Saudi Arabia into a conversation about nuclear weapons.<\/p>\n

The Two<\/strong> P<\/strong>lus<\/strong>\u00a0<\/strong>Four <\/strong>Agreement<\/strong><\/p>\n

The NPT is linked to the 2+4, which made reunification possible, confirmed Germany\u2019s borders as final, and restored its full sovereignty. The 2+4 does not contain an \u201copt-out clause\u201d and can thus be viewed as stronger in international-law terms\u00a0than the NPT.\u00a0The European Nuclear Study Group\u2019s\u00a0(ENSG) \u201cMind the Deterrence Gap<\/u><\/a>\u201d report\u00a0confirmed this, stating the 2+4 \u201cforbids any form of German control over nuclear weapons,\u201d though noting \u201csome German commentators have recently questioned whether this provision should remain in force.\u201d<\/p>\n

Here, too, a closer look is necessary. Article 3(1) consists of three sentences:<\/p>\n

\u201cThe Governments of the [FRG] and the [GDR] reaffirm their renunciation of the manufacture and possession of and control over nuclear, biological and chemical weapons. They declare that the united Germany, too, will abide by these commitments. In particular, rights and obligations arising from the [NPT] will continue to apply to the united Germany.\u201d<\/p>\n

On\u00a0an initial reading, sentence 1 appears to be an explicit declaration imposing the renunciation as a new obligation. The Bundestag\u2019s Research Service, however, reads it as doing the opposite: confirming that the 2+4 did not impose any new obligations on the united Germany (WD 2-3000-008\/24<\/u><\/a>). The affirmation, it argued,\u00a0is merely \u201cdeclaratory\u201d\u2014a\u00a0reminder to adhere to existing obligations. The Service subsequently confirmed this\u00a0(WD 2-3000-060\/24<\/u><\/a>).<\/p>\n

The Service\u2019s understanding is based on the NPT, not on Germany\u2019s earlier commitments (Adenauer\u2019s 1954 declaration, carried into the Paris Agreements); whether those older commitments retain independent force today\u2014bound up with arrangements since superseded\u2014is a separate question this commentary does not pursue. What a withdrawal from the NPT would leave standing is thus not fully settled; however, sentence 3 preserves the right to withdraw under Article X of the NPT.<\/p>\n

Sentence 2 could be read as imposing new obligations on a united Germany\u2014in line with the Four Powers\u2019 demand for a renunciation of nuclear weapons in exchange for reunification. This maximalist interpretation would go beyond sentence 1 and could effectively nullify Article X as an option for Germany. One could also interpret sentence 2 as merely extending sentence 1 to a united Germany.<\/p>\n

Germany\u2019s <\/strong>O<\/strong>ptions<\/strong><\/p>\n

The ENSG\u2019s report evaluates five options for Europe: (1) U.S. extended nuclear deterrence; (2) French\/U.K.-based European nuclear deterrence; (3) a Eurodeterrent; (4) new, independent national nuclear deterrents; and (5) no nuclear deterrent. Its verdict: Europe faces no good options, only less bad ones. Each affects Germany differently and is worth considering.<\/p>\n

Regarding option 2, in February 2026<\/u><\/a>,\u00a0German Chancellor Friedrich Merz said he did not want Germany to consider developing its own nuclear weapons, but that the standing French offer could not be left unexamined, and asked whether France and the U.K. might match the U.S. umbrella. On 2 March 2026, the German government confirmed<\/u><\/a> that Germany and France had \u201cestablished a high-ranking nuclear steering group\u201d but would \u201ccontinue to comply with their obligations under international law including the [NPT].\u201d Yet, on the same day, President Macron ruled out<\/u><\/a> any joint planning, execution, or final authorization of use\u2014precisely what the U.S. \u201cdual-key procedure\u201d allows. Nevertheless, Germany could provide financial support for France\u2019s nuclear weapons, as the NPT does not preclude this.<\/p>\n

However, France will elect a new president by April 2027; should\u00a0the far-right Rassemblement National win, any eventual arrangement\u00a0could be overturned, and a victory of the political left also carries this risk.\u00a0Even if such a Franco-German\u00a0agreement survived the election, it would be far more politically sensitive than the Future Combat Air System, whose\u00a0manned-fighter core\u2014despite active involvement from France, Germany, and Spain\u2014was abandoned on 8 June 2026<\/u><\/a> after nearly a decade.<\/p>\n

The British situation is more complicated than the French, as the U.K. depends on the U.S.\u2014which provides the Trident missiles. This brings us back to option 1: the U.S. itself is the source of much of Germany\u2019s uncertainty.\u00a0 In early June 2026, reporting suggested the U.S. would cancel<\/a> the planned sale of Tomahawk missiles to Germany, reportedly over fears Russia would see the sale as escalation (in July, however, Merz announced an agreement<\/a> to acquire Tomahawks\u2014a letter of intent signed at the Ankara NATO summit, with U.S. approval promised for August). This reporting emerged roughly a month after the U.S. announced, on 1 May 2026,\u00a0the withdrawal of 5,000 troops<\/u><\/a> from Germany\u2014which followed Merz\u2019s\u00a0criti<\/u>cism<\/u><\/a>\u00a0of the U.S. strategy toward Iran.<\/p>\n

If the U.S. invokes\u00a0fears over Russian escalation to withhold conventional capabilities, this\u00a0undermines\u00a0the credibility of the U.S. extended nuclear deterrence for Germany. Meanwhile, a Eurodeterrent is politically all but impossible,\u00a0lacks a plausible configuration,\u00a0raises NPT-compliance questions, and carries a high risk of decision paralysis.<\/p>\n

“Zweigleisigkeit”<\/strong><\/p>\n

Given these uncertainties, option 4 warrants attention. The ENSG report lists legal constraints among the feasibility limits that render some options unlikely; for Germany, that constraint is Article 3.\u00a0In the 2+4 talks, Germany traded the option of nuclear weapons\u00a0for\u00a0reunification. The NPT Review Conference failure opens the possibility of securing a comparable bargain\u00a0via\u00a0Zweigleisigkeit<\/em>, a strategy of holding two complementary negotiating positions: simultaneously seeking\u00a0a credible legal route out of Article 3 of the 2+4\u00a0while\u00a0offering\u00a0to renegotiate the nuclear order.<\/p>\n

On the one hand, Germany may not wish to alter the nuclear order\u00a0but might be forced to consider clausula rebus sic stantibus<\/em>\u2014the doctrine that a fundamental change of circumstances can call\u00a0the promises of 1990 into question.\u00a0This clause forms the basis of Article 62 of the Vienna Convention on the Law of Treaties<\/u><\/a> (VCLT).<\/p>\n

During unification, as Robert Zoellick wrote in 2000<\/u><\/a>, \u201cAmerica\u2019s strategic aim was to promote peace and security [\u2026] by pressing for Germany\u2019s unification within the European Community and NATO.\u201d\u00a0Zoellick noted that\u00a0Gorbachev told Bush at Malta in December 1989 he wanted U.S. troops to stay in Europe; Bush replied they would remain only as part of NATO, so a continued U.S. presence depended on a healthy alliance.\u00a0Should the U.S. now step back from defending Europe\u2014as the developments above suggest\u2014the calculus that underpinned the 2+4 would change.<\/p>\n

But\u00a0further complications arise: the VCLT might not be applicable to the 2+4 due to Article 4 VCLT\u00a0limiting application to treaties concluded after the Convention\u2019s entry into force with regard to the parties,\u00a0since France and the U.S. never ratified the VCLT; but Article 62 VCLT binds as customary law regardless\u00a0(see ICJ, Fisheries Jurisdiction<\/em>, 1973\u00a0para. 36<\/u><\/a>; Gab\u010d\u00edkovo-Nagymaros<\/em>, 1997\u00a0paras. <\/u>46, <\/u>99-104<\/u><\/a>). Moreover, the Service rejected Article 62\u00a0on two grounds: in February 2024 (WD 2-3000-008\/24<\/u><\/a>)\u00a0it found no objective change in external circumstances\u2014attitudes and new alliances, it held, do not qualify\u2014and it inclined toward classifying the 2+4 as a border-establishing treaty under Article 62(2)(a) VCLT. The first finding predates the developments above, which are conduct rather than attitudes\u00a0(a May 2026 brief, EU 6-3000-070\/26<\/u><\/a>, restates the 2024 analysis without engaging this conduct).<\/p>\n

However, it would likely be consistent with the VCLT to distinguish between the border clause and other obligations under the 2+4, since Article 62(2)(a) VCLT\u00a0protects the stability of the border demarcation itself, but does not entirely preclude Article 62(1) VCLT\u00a0as a reason for terminating the treaty. Furthermore, the issue would not be to alter Germany\u2019s borders\u2014these are separately confirmed by treaty with Poland\u2014but to recognize that the same \u201cextraordinary events\u201d justifying withdrawal under Article X of the NPT could also be relevant as a \u201cfundamental change of circumstances\u201d within the meaning of Article 62(1) VCLT.<\/p>\n

Article 44(3) VCLT, or a comparable customary procedure, then provides for the separability of treaty provisions.\u00a0Severance of Article 3 of the 2+4 would thus be feasible in principle. Most obligations were tied to unification and are, on the Service\u2019s account, now obsolete; what continues (WD 2-3000-061\/24<\/u><\/a>) is Germany\u2019s own renunciation under Article 3, alongside the Article 5(3) ban\u2014which, too, binds the three Western powers\u2014on\u00a0stationing foreign forces or nuclear weapons in the former GDR.<\/p>\n

Germany has reaffirmed its commitment repeatedly since reunification, but this does not change the analysis. Under international law, the possibility of invoking clausula rebus sic stantibus<\/em> exists independently of political declarations\u2014provided there is no breach of good faith. That invocation would be the \u201cnuclear option\u201d: Article 62 VCLT would then provide grounds for severing Article 3 of the 2+4 alone, while Article 44(3) VCLT would provide the mechanism.<\/p>\n

On the other hand,\u00a0the NWS could create a new nuclear balance and take Germany\u2019s concerns\u2014and those of other NNWS\u2014seriously, so that\u00a0Germany\u00a0need not sever Article 3 of the 2+4. But the failed conference indicates that this is currently unlikely\u2014unless a state like Germany exerts pressure, as this\u00a0Zweigleisigkeit<\/em> would allow.<\/p>\n

Consequences<\/strong><\/p>\n

In January<\/u> 2026<\/u><\/a>, Merz invoked the 2+4 and the NPT, concluding that\u00a0the question of nuclear weapons lies outside Germany\u2019s discretion. He held to that position in February. The political conclusion thus rests on a legal premise\u2014and that premise is less firm than it appears. Germany has options.\u00a0But to make use of them, Germany\u00a0must understand the international legal position precisely and acknowledge that its\u00a0obligations are not as immovable as some assume.<\/p>\n

The author is grateful to Professor Oliver D\u00f6rr for his help in understanding Article 3 of the Two Plus Four Agreement and Articles 44 and 62 VCLT, and for his critical reading of an earlier draft, which saved the piece from errors of substance and emphasis alike. He also thanks the anonymous reviewer and the V\u00f6lkerrechtsblog editorial team. The argument and any errors that remain are the author’s alone.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Under international law,\u00a0Germany is not as irrevocably barred from acquiring nuclear weapons as is commonly assumed. In certain circumstances, Germany could be released from Article 3 of the Treaty on the Final Settlement with Respect to Germany (known as the Two\u00a0Plus\u00a0Four Agreement, or 2+4) and withdraw from the Non-Proliferation Treaty (NPT). This would allow Germany […]<\/p>\n","protected":false},"author":35,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[6639],"tags":[3717,5122,6015,6028],"authors":[8072],"article-categories":[6000],"doi":[],"class_list":["post-29380","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-germany","tag-non-proliferation","tag-nuclear-weapons","tag-vienna-convention-on-the-law-of-treaties","authors-gabriel-h-heyl","article-categories-article"],"acf":{"subline":"Germany\u2019s Legal Latitude After the NPT Review Conference Failure"},"meta_box":{"doi":"10.17176\/20260723-190050-0"},"_links":{"self":[{"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/posts\/29380","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/users\/35"}],"replies":[{"embeddable":true,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/comments?post=29380"}],"version-history":[{"count":6,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/posts\/29380\/revisions"}],"predecessor-version":[{"id":29430,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/posts\/29380\/revisions\/29430"}],"wp:attachment":[{"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/media?parent=29380"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/categories?post=29380"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/tags?post=29380"},{"taxonomy":"authors","embeddable":true,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/authors?post=29380"},{"taxonomy":"article-categories","embeddable":true,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/article-categories?post=29380"},{"taxonomy":"doi","embeddable":true,"href":"https:\/\/voelkerrechtsblog.org\/de\/wp-json\/wp\/v2\/doi?post=29380"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}