Harold James calls Trump and Boris Johnson “nihilistic imposters” who embrace “radicalism”, while claiming to act in the name of conservatism. Yet “genuine” Anglo-American conservatism is intertwined with the ideals of Edmund Burke, the 18th-century political philosopher, whose noblesse oblige conservatism was rooted in honour, loyalty and duty.

Unfortunately these Burkean conceptions of moral community and social value have “long served as a source of frustration for readicals, and as a necessary restraint against destructive root-and-branch reforms.” The fate of the UK and the US is often said to be inextricably linked. Engulfed by a populist tide, the Tory-led Britain voted to leave the EU in June 2016; and later that year, the November election propelled the Republican candidate, Trump to victory.

The author points out another “eerie coincidence.” On September 24, House Speaker Nancy Pelosi announced a formal impeachment inquiry into Trump, who was in New York for the opening of the UN General Assembly. This historic move came on the same day the UK Supreme Court ruled that the suspension of Parlimanet was unlawful. Johnson was delivering a speech before the UN, hailing Britain as “the best place in the world” to do business, moments after the humiliation.

It comes as no surprise that Trump’s election and Brexit had in “remarkably similar ways and almost at the exact same time…. destroyed transatlantic conservatism.” According to the author, “American conservatism has always had rather shallow roots,” while “British conservativism is the product of a long and rich intellectual tradition, which makes its demise all the more astonishing.” But in recent years, the world has seen the decline of traditional conservatism, and amid its deepening crisis, the rise of Trumpian populism.

In Britain traditional Conservatives are averse to “radical change” but they are pragmatic enough to adapt themselves to reality and willing to accept “a piecemeal approach to reform” while rejecting “the wholesale uprooting of institutions, on the grounds that sweeping change is too hard to control.” But the radical far-right, who clamour for change, often fall for “promises of a magic fix to any problem.” In the UK Brexiteers have found in Johnson a leader with Trump’s swagger.

In the past, “radically inclined Labourites as well as ultra-Tories” viewed conservative “pragmatism and the search for consensus” as a thorn in their side, complaining that the major parties had become “a near-identical confection” of “Butskellism” – a term popularised during the 1950s, by merging the names of two successive Chancellors of the Exchequer, Labour's Hugh Gaitskell (1950–1) and the Conservative R. A. Butler (1951–5). Both favoured a ‘mixed economy’, a strong welfare state, and Keynesian demand management designed to ensure full employment.

The author says, Margaret Thatcher broke the post-war consensus with her new fusion of disruptive capitalism and social traditionalism, but remained “surprisingly faithful to gradualism.” She took on the trade unions and other instiutions one by one. “Had she challenged them all at once, she probably would have failed.” She saw in the European integration “a powerful mechanism for making incremental, but ultimately quite far-reaching, progress toward a more liberal economic order.”

Sadly, Trump and Johnson lack the patience and acumen to deal with crises. Instead of resolving them step by step, their approach likens to cutting the Gordian knot in one blow. They call for a fundamental change in politics like “restoring sovereignty” and looking out for their own national interests.

In the UK, Brexit has transformed the country’s political tradition. Diehard Brexiteers have fomented hostility against the very institutions that made Britain sovereign: parliamentary democracy and the rule of law. Like their counterparts in the US, they have become imprisoned by nostalgia, ignoring demographic changes.

Since the 90s, Britain and the US have steadily become more urban, multiracial, more connected to the outside world. Meanwhile, support for the Tories and the Republicans has grown ever more concentrated in towns and rural areas, and among white, elderly men. Their fear of becoming a minority has been hijacked by white supremacists and far-right nationalists.

In Britain there are Conservatives who stand up to Johnson’s Brexit policy. In the US only a handful of Republicans who muster enough courage to defy Trump. The coming months will be crucial for the GOP. It remains to be seen whether Republicans choose to be on the wrong side of history.