In a world increasingly defined by shifting alliances and global fragmentation, international tax cooperation has become a bellwether for the viability of multilateralism. At a recent event hosted by the Australian Institute of International Affairs Queensland (AIIAQ), the Honourable David Bradbury—former Deputy Director of the OECD’s Centre for Tax Policy and Administration—reflected on his pivotal role in shaping the Base Erosion and Profit Shifting (BEPS) project. His reflections not only outlined the remarkable progress achieved but also underscored the structural vulnerabilities that continue to plague international consensus.

The BEPS project was launched after the 2008 Global Financial Crisis, as growing public scrutiny fell upon multinational corporations exploiting tax mismatches across jurisdictions. With backing from the G20, the OECD initiated a 15-point Action Plan to reduce cross-border tax avoidance. Hon. Bradbury highlighted that fourteen of these measures were successfully implemented, reshaping international tax standards and representing what he described as “a transformative milestone” in global governance.

However, the most politically sensitive issue remained unresolved: the taxation of the digital economy. Under traditional rules, companies were taxed only where they had a physical presence, allowing digital giants to reap massive profits across borders while paying little tax. Although a growing number of nations favoured reform, the United States—particularly under the Obama administration—resisted any move to alter the status quo. As a result, consensus on “Pillar One”, which aimed to reallocate taxing rights in the digital age, remained out of reach.

Ironically, momentum resurfaced under the Trump administration. The introduction of the GILTI (Global Intangible Low-Taxed Income) regime in 2017 marked a unilateral U.S. initiative to curb tax avoidance by its own multinationals. While domestically focused, GILTI helped normalise the concept of a minimum corporate tax, ultimately laying the foundation for “Pillar Two”—a global minimum tax agreement.

This second pillar was widely hailed as a breakthrough. Under its terms, multinational enterprises with revenues exceeding €750 million would be subject to a minimum effective tax rate of 15% on global profits. Hon. Bradbury commended the agreement’s design, which included a “top-up” mechanism: if profits were taxed below the threshold in one jurisdiction, another country could collect the difference. This disincentivised the use of tax havens, creating a system where relocation of profits no longer conferred a strategic advantage.

Yet, despite its robust architecture, the global minimum tax was politically vulnerable. While the Biden administration initially endorsed the deal, the return of nationalist rhetoric under “Trump 2.0” saw the U.S. withdraw its commitment. The administration even threatened retaliatory tariffs against countries enforcing the agreement in ways that could impact U.S. corporations. Hon. Bradbury observed, “There’s not much you can do to bulletproof a system against that sort of attack.”

This sudden reversal triggered renewed frustration among many Global South nations, who began to question whether their participation in the OECD’s Inclusive Framework reflected shared decision-making—or merely legitimised a U.S.-dominated agenda. In response, some called for international tax negotiations to shift to the United Nations, a body with a more egalitarian governance model. However, Hon. Bradbury was pragmatic. While recognising the appeal of the UN, he emphasised that its lack of legal and technical infrastructure would render any reform ineffective without cooperation from major economies. “You can outvote them,” he remarked, “but unless they agree to change their tax treaties, it won’t change anything.”

Beyond the technicalities of tax reform, Hon. Bradbury used his experience to extract broader lessons about the limits and possibilities of multilateralism in today’s fractured world. The collapse of political support for international tax cooperation, particularly from the United States, revealed a stark truth: even the most carefully designed global frameworks remain hostage to shifting national interests. As Hon. Bradbury noted, the United States—home to a disproportionate share of the world’s largest and most profitable multinationals—has always held a de facto veto over any global tax agreement. Without U.S. buy-in, truly effective global enforcement becomes nearly impossible.

This reality has led to growing disillusionment among countries, particularly within the Global South, about the legitimacy and effectiveness of institutions like the OECD. Hon. Bradbury observed that as the U.S. increasingly dominated negotiations, many nations began exploring alternative venues, such as the United Nations, where governance would be based on majority votes rather than consensus among a smaller, elite group. Yet even this shift, he cautioned, is limited in practical effect—international tax rules still depend on the voluntary renegotiation of bilateral treaties, which majority votes cannot compel.

Hon. Bradbury stressed that overplaying political strength in multilateral negotiations can have unintended consequences. As the U.S. pushed its interests, it stretched the cooperative fabric of the OECD framework to its breaking point, leading to a fragmentation of global consensus. This, he suggested, mirrors a broader erosion of trust in multilateral institutions across issue areas—from trade to climate change to security.

Reflecting on Australia’s role, Hon. Bradbury warned against complacency. He argued that middle powers like Australia must adopt a more proactive and creative approach to global engagement in an increasingly polarised international system. He advocated for a model of “plurilateral”—where like-minded states with shared values and common challenges band together to forge cooperative solutions, even if universal consensus is unattainable. Such coalitions, though smaller, may offer a more realistic path forward in a world where global governance structures are faltering.

Hon. Bradbury also touched on the strategic use of crises as catalysts for reform. The 2008 Global Financial Crisis created a rare moment of international unity and public demand for fairness, enabling the BEPS project launch. He warned, however, that such “windows of opportunity” are fleeting. The lesson: nations must do the policy groundwork early to act when the moment arrives.

In concluding his remarks, Hon. Bradbury expressed concern over the erosion of democratic institutions, growing populism, and the disruptive force of technological change—especially artificial intelligence. These dynamics, he suggested, compound existing geopolitical fragmentation and make long-term cooperation more elusive. Nevertheless, Hon. Bradbury struck a note of guarded optimism.

“If we leave like-minded countries to fend for themselves, we should not be surprised when no one comes to our aid.”

He warned: multilateralism, though weakened, remains essential. But its future will depend on reimagining cooperation—not as a one-size-fits-all system, but as a flexible, value-driven framework resilient to the pressures of a changing world.

In sum, Hon. David Bradbury’s reflections serve as a timely reminder: the architecture of global cooperation may be straining, but the need for it has never been greater.

Edited by Deborah Bouchez 

Written by Kiseki Fujisawa

Currently, in her final year of a Juris Doctor at Griffith University, Kiseki Fujisawa is passionate about international law and global affairs. With a strong interest in the intersection of law and diplomacy, Kiseki aspires to promote justice and peace worldwide through legal and diplomatic efforts.