On Thursday 12 July 2018, US president Donald Trump, the most dangerous man in the world, was welcomed to the United Kingdom by the British prime minister Theresa May. The following day the streets of London witnessed the biggest protest for over a decade as thousands marched on Trafalgar Square to express their anger at the British government extending a red carpet welcome for Trump.

Protesters pointed out the extreme threat to democracy, to those dependent on welfare, to womens' rights, to civil rights generally and even to the survival of humankind which Trump presents. Such assertions might seem extreme, but they are unfortunately fully justifiable.

As the president of what is by far the richest and most powerful country on earth, Trump has dedicated his term to accelerating the US addiction to fossil fuels and agribusiness, dismantling the Environmental Protection Agency and withdrawing America from the Paris Climate Accords, thereby accelerating global warming and climate change and presenting a huge threat to the continued existence of humankind.

Trump's presidency also marks another dangerous step in the erosion of democracy in the United States. Far from "draining the swamp" as he promised, Trump has surrounded himself with powerful figures from big business, especially major financial institutions such as Goldman Sachs, as well as his friends and allies in the fossil fuel and defence industires.

Government policy, more and more, reflects the direct interests of concentrated private power with the public having less and less influence. At the same time the Trump presidency has allied itself with some of the most ruthless regimes in the world and is profiting from Saudi Arabia's illegal war of aggression in Yemen which has created the world's worst humanitarian crisis. A serious war crime in which Donald Trump and Theresa May are both complicit.

Trump has also been keen to patronise the extreme nationalist constituency in the United States and through preaching a propaganda of fear his presidency has managed to oversee some of the most racist immigration policies ever to be implemented in the United States, targeted almost exclusively at Muslim countries - Iran, Libya, Somalia, Syria and Yemen. Ironically, all of them have been massively destabilized and impoverished by US foreign policy.

He was also responsible for the ruthless decision to separate children from their parents as they cross into the United States from Mexico, in his determination to block immigration from central America, where decades of US illegal intervention, including the CIA funded Contra terror operations in Nicaragua and enforced free trade (under NAFTA or IMF rules) have devastated the region and merely enhanced the power of corrupt corporate elites and drug cartels.

As if this was not enough to worry about, Trump has also authorized a huge increase in both US defence spending and in the US nuclear arsenal, and changed the strategic posture of the US so that nuclear weapons can be used even for offensive operations and even when their use is not required to preempt a nuclear strike by an enemy power.

As any historian of conflict since the Second World War knows, it is only by a miracle that humankind has survived since 1945 without a nuclear war. Now the situation is more dangerous than ever before. Not only are we are now dependent on Trump's extremely unpredictable temperament but also increasingly on automated systems which can easily malfunction.

Trump and Republicans maintain they need to spend heavily on military equipment in order to counter the supposed Russian threat. However they seldom remind the public that the United States already spends almost as much as the rest of the world combined on defence and that Russia's expenditure is far behind both that of the United States and only on about the same level of Saudi Arabia, and spends only 10% of what NATO spends.