Pakistan — described by TIME magazine in 2004 as home to a “nuclear bazaar” run by the “man who sold the bomb” — has now re-emerged as a trusted intermediary in the Iran-US ceasefire.The description was not journalistic exaggeration — it was a statement of fact.Abdul Qadeer Khan, the architect of Pakistan’s nuclear programme, built what TIME reported in 2004 as “a vast, clandestine and hugely profitable enterprise”, selling nuclear technology to a “rogues’ gallery of nations”, including Iran.This was not leakage. It was business.At the centre of that business were uranium enrichment centrifuges, the machines that make a nuclear weapons programme possible. Pakistan’s programme developed two key models — known as the P-1, and the more advanced P-2 centrifuges — capable of enriching uranium to weapons-grade levels. These were not theoretical designs. They were exported.Investigations by international inspectors and subsequent analysis established that P-1 centrifuge designs — and, later, the more advanced P-2 variants — were transferred through Khan’s network to Iran, forming the backbone of its early enrichment programme. The same network supplied Libya with centrifuge components, including pre-assembled machines and parts for hundreds more, alongside technical documentation and expertise.This was not a marginal contribution. It was foundational.Clients were offered what one intelligence official described as “the whole package” — centrifuge designs, components, manufacturing know-how and technical expertise.Iranian intermediaries arrived with “suitcases containing $3 million in cash”. Individual deals ran to $100 million. Components were manufactured in Malaysia, routed through Dubai, assembled across continents and delivered through a network of shell companies that sometimes consisted of little more than a fax machine and an empty office.This was not proliferation in the abstract. It was a supply chain.Nor was this simply a Western allegation. Reporting in January 2004 in The News International — a Pakistani English-language daily — cited investigators linking Khan to “international black market dealers”, who supplied nuclear technology and hardware to Iran and Libya.The same reporting stated that Khan authorised the transfer of “blueprints and names of third party contacts” to Iranian authorities, and later helped Iran produce centrifuges for uranium enrichment.In other words, Iran’s nuclear capability was not merely observed by Pakistan. It was, in part, built on Pakistani designs.The most troubling aspect was not the activity itself, but the environment in which it took place. Pakistani officials acknowledged “negligence, financial impropriety and security lapses” at the highest levels of the Khan Research Laboratories. Intelligence sources spoke of a system in which “army chiefs and intelligence services looked the other way”, while money from Iran flowed into the personal accounts of Pakistani scientists.Khan himself, according to one account, “was never supposed to answer or explain his most frequent trips”.This was not a rogue scientist slipping through the cracks. It was a system that functioned because the cracks were left open.The scale of the operation eventually forced a response at the highest level. In 2004, then US President George W Bush described the network as “the world’s most dangerous proliferation ring”. The language matters. It was not peripheral. It was central.And yet the system proved remarkably resilient. Even after its exposure, investigators warned that elements of the network persisted. As one assessment noted, “it’s still a seller’s market in the nuclear bazaar”.The infrastructure — the contacts, the expertise, the routes — did not simply disappear.It is against this background that Pakistan’s current diplomatic role must be understood.The pivot came in June 2025, when Donald Trump hosted Pakistani army chief Asim Munir for a private lunch at the White House. The meeting, unusual in both form and substance, established a direct channel between Washington and Pakistan’s military leadership, bypassing the rituals and constraints of formal diplomacy.Trump has since spoken of Munir in strikingly personal terms, calling him his “favourite Field Marshal” and suggesting that he understands Iran “better than most”. Stripped of theatrics, the message was simple: Pakistan had access.Trump’s language makes the hierarchy clear. NATO allies have been dismissed as “delinquent” and publicly scolded; Pakistan’s army chief, by contrast, is a “favourite Field Marshal”.In this calculus, alliances matter less than usefulness.That access has now translated into leverage. In the final hours before the ceasefire, a Pakistani source told the BBC that talks between Washington and Tehran were continuing “at pace”, with Pakistan acting as an intermediary. Officials in Islamabad spoke of efforts “to manage things as much as possible”, while the Prime Minister described diplomatic engagement as “progressing steadily, strongly and powerfully”.The phrasing is cautious. The implication is not. Pakistan was in the room — if not physically, then operationally.Why Pakistan? Why not Britain, America’s closest ally, or India, its emerging strategic partner?Because neither occupies the same space. The United Kingdom is too closely aligned with Washington to act as an intermediary; it speaks with, not between.India, for all its strategic weight, lacks the necessary trust in Tehran, and is seen through the lens of regional rivalry.Pakistan is different. It has a shared border with Iran, a long and complicated relationship with Tehran, and — crucially — a historical connection to Iran’s nuclear infrastructure that no other country can match.That raises an uncomfortable question.If Pakistan once supplied the designs and components that underpinned Iran’s centrifuge programme, is it now helping to manage — or even constrain — the consequences of that same technology?The irony is unavoidable. The country that exported the machinery of enrichment now positions itself as a broker in a crisis defined by enrichment risk. The supplier has become the intermediary.This is not a story of redemption. It is a story of continuity.Pakistan’s influence today does not stem from moral authority. It stems from decades spent operating in the grey areas of international politics — building networks, maintaining relationships, and cultivating access where others hesitated.In that world, credibility is not the decisive currency.Access is.And Pakistan, for all its contradictions, has it.Influence, in such environments, does not flow from purity. It flows from access, from relevance, and from a willingness to engage where others hesitate.Pakistan has spent decades cultivating that space. Today, it is reaping the dividends.