The law as a convenient fiction: How legal arguments have facilitated British and American foreign policy failures

Illustration by Will Allen/Europinion

The law has long served as both a shield and a smoke screen, selectively wielded to justify both strategic retreats and upholding obligations. Rarely an impartial force, the legal dimension of UK and US foreign policy has been increasingly shaped by political will. The recurring iteration of the UK’s EU policy pandemonium parallels that of America’s isolationist legalism pre-WWII and President Trump’s NATO scepticism. They all similarly deploy legal justification to obscure deep policy failures.  

Then, as now, leaders invoked the law to rationalise inaction, disguising recklessness as legality. While figures like Boris Johnson and Donald Trump champion national sovereignty, their legal battles over international commitments expose a contradiction — law, ostensibly a safeguard, is weaponised to enable withdrawal rather than uphold responsibility. 

The UK Supreme Court’s ruling in Miller (No. 1) (2017) epitomised legalism as a shield for political failure. By ruling that parliamentary approval was required to trigger Article 50, the Court reaffirmed the constitutional principle that major changes to citizen’s rights could not be enacted through executive power alone. While framed as a victory for democracy, this legal scrutiny slowed Britain’s departure from the EU, prolonging uncertainty and weakening its bargaining position. This legal entanglement set the stage for post-Brexit manoeuvring, where law was invoked not as a stabilising force but as a tool to justify strategic missteps. The Internal Market Bill (2020), which sought to override elements of the Withdrawal Agreement, exemplified how Brexit-era legalism masked political contradictions. Nowhere was this clearer than in the Northern Ireland Protocol, where international commitments clashed with domestic pressures, forcing the UK to retreat behind legal arguments to rationalise treaty breaches. This legalistic approach was particularly ironic given that Brexit was sold as a reclamation of sovereignty—yet, when faced with the complexities of self-imposed isolation, Britain’s leaders weaponised the very legal constraints they once sought to escape.

Britain's history of flailing around legalistic loopholes has long cast a shadow over its Europe policy. Such a pattern echoes Prime Minister Harold Macmillan’s blundering attempts to secure British entry into the European Economic Community (EEC) in the 1960s. Much like the Brexit-era, Britain believed it could shape its relationship to Europe through legal means, without fully committing to the realities of integration. French president De Gaulle vetoed both attempts in 1963 and 1967, believing that Britain’s economic model and Atlanticist loyalties made it an unsuitable partner. At the time, Britain’s membership in the European Free Trade Association (EFTA) created a legal tension, as joining the EEC required it to abandon conflicting trade commitments. Although the EEC's legal accession requirements could be met, the political resistance, particularly from France, framed as a legal obstacle, delayed Britain's ability to formally begin the process of joining, masking deeper political issues. In both cases, legal mechanisms were used to navigate political realities—whether to maintain control over trade agreements or to push through Brexit—but these legal moves concealed underlying political struggles over national sovereignty and the UK's position in Europe. 

Illustration by Will Allen/Europinion

The Miller ruling and subsequent Brexit legal battles ultimately exposed the contradictions at the heart of Britain’s foreign policy. Just as Macmillan’s legalistic approach failed to win European acceptance, Brexit-era legal manoeuvring could not insulate Britain from the geopolitical consequences of its departure. The Brexit issue was never just a legal question—it was a geopolitical reckoning that Britain sought to evade through legal wrangling, distracting from its declining diplomatic leverage. The law, instead of offering clarity, became an instrument to rationalise retreat, avoiding confronting Britain’s diminished global influence.

The U.S. under Trump provides a similarly striking example of how legalistic arguments can be weaponised to undermine strategic commitments. His approach to NATO, framing alliance contributions as debts and citing financial unfairness under Article 5—was not merely a misrepresentation of NATO’s collective defence principles but an explicit attempt to erode its credibility. This legal formalism is serving as a pretext for strategic disengagement, mirroring America’s isolationist tendencies of the 1930s. Then, neutrality laws codified non-intervention under the guise of legal prudence, yet in practice, they emboldened aggressors by signalling American reluctance. Trump revived this tradition, using legal arguments not as a means of strengthening alliances but as a tool to justify withdrawal. By insisting that NATO allies “owed” the U.S. money—a claim fundamentally misaligned with NATO’s burden-sharing framework—Trump distorted legal obligations to suit a transactional, America-first agenda. This redefinition of alliance politics through legalistic semantics reflects a broader trend: legal arguments, rather than clarifying commitments, are increasingly wielded to rationalise the abdication of global responsibility.

The legal constraints surrounding NATO expansion have operated as instruments of diplomatic inertia rather than safeguards. The U.S. Senate treaty ratification process, whilst constitutionally mandated, has been reified into a strategic bureaucratic obstacle rather than to ensure rigorous oversight. Legal formalities work to obstruct an urgent geopolitical necessity, particularly evident in the delayed ratification of Sweden and Finland's NATO accession. Despite broad political consensus within NATO following Russia’s invasion of Ukraine, the process was slowed by Turkey and Hungary's protracted approval, which leveraged their ratification to extract political concessions. Rather than enforcing alliance strength, these procedural hurdles subjected NATO to American internal political gridlock. Instead of facilitating decisive action, legal frameworks engender self-sabotaging mechanisms that fuel political leverage rather than strategic clarity.

Illustration by Will Allen/Europinion

The recurring flaw in both UK and US foreign policy is the illusion that legal manoeuvring can mask—or even replace—strategic clarity. History is rife with leaders who have cloaked strategic retreat in legal justifications, only to find themselves tangled in their own legal webs. Brexit and Trump’s NATO posturing are not anomalies but continuations of this pattern: when states lack a coherent geopolitical vision, they retreat into legalism as a crutch for indecision. The legalistic battles over Brexit negotiations and NATO commitments should be recognised for what they are—excuses for weak and directionless foreign policy. Britain and America have not erred by ignoring the law but by treating it as a rigid doctrine rather than a flexible instrument of statecraft. When legalism becomes a substitute for strategy, it does not safeguard national interests—it erodes them, enabling diplomatic missteps and global instability.

The real question is not whether Brexit and NATO debates conform to legal principles, but whether they serve a meaningful strategic purpose. If history is any guide, legal arguments alone will not prevent foreign policy failures—only political will and strategic foresight can.