Bustling, buzzing and bartering. That is how I would once have described a typical market (or souk) in Yemen.

Not any longer. These days they’re often barren and lifeless. During my many visits, I’ve seen the devastation of once busy souks destroyed by Saudi coalition airstrikes. Skeletal structures of buildings and stalls lie empty where once vibrant businesses sold coffee, spices, locally-grown fruits and vegetables, clothes and children’s toys.

By contrast, on the other side of the world a lucrative market in high-tech weaponry is positively thriving. Over the past two years, the UK and the US have sold billions of pounds’ worth of arms to Saudi Arabia, arms used to obliterate Yemeni markets and much else.

In Yemen, I’ve met countless victims of airstrikes who’ve lost loved ones or had livelihoods destroyed, leaving them impoverished and destitute. After two years of this, the country is facing a humanitarian disaster of epic proportions, with more than 18 million Yemenis requiring humanitarian assistance.

On the one hand, the UK and US have supported Yemen with around £371.5m in aid during the past two conflict-ridden years. On the other, British and American arms companies, with the authorisation of the UK and US governments, have busily supplied much of the weaponry that Saudi Arabia has used for its devastating attacks in its southern neighbour.

The situation in Yemen Show all 14 1 /14 The situation in Yemen The situation in Yemen Houthi supporters trample on a US flag during a gathering mobilizing more fighters into several Yemeni battlefronts, in Sana'a, Yemen EPA The situation in Yemen People carry the coffins of men, who were killed in the recent Saudi-led airstrikes during their funeral, in the Old City of Sanaa, Yemen AP The situation in Yemen Pro-government fighters give food to Yemeni children on the road leading to the southwestern port city of Mokha. Yemeni rebels are putting up fierce resistance in a key Red Sea port city where they are encircled by pro-government force Getty Images The situation in Yemen A Yemeni stands in front of a graffiti protesting US military operations in war-affected Yemen, in Sana'a, Yemen. According to reports, US Special Forces troops allegedly disembarked from US helicopters in the Yemeni town of Yakla and attacked several houses belonging to members of the terrorist group Al-Qaeda, killing three high-ranking Al-Qaeda members and nine civilians, six women and three children. One American serviceman has been killed and three injured in the attack EPA The situation in Yemen US Special Forces troops allegedly disembarked from US helicopters in the Yemeni town of Yakla and attacked several houses belonging to members of the terrorist group Al-Qaeda, killing three high-ranking Al-Qaeda members and nine civilians, six women and three children. One American serviceman has been killed and three injured in the attack EPA The situation in Yemen A Yemeni female fighter supporting the Shiite Huthi rebels, and carrying weapons used for ceremonial purposes, takes part in an anti-Saudi rally in the capital Sanaa Getty Images The situation in Yemen Yemeni female fighters supporting the Shiite Huthi rebels, and carrying weapons used for ceremonial purposes, take part in an anti-Saudi rally in the capital Sanaa Getty Images The situation in Yemen A boy shouts slogans next to pro-Houthi fighters, who have been injured during recent fighting, during a rally held to honour those injured or maimed while fighting in Houthi ranks in Sanaa, Yemen Reuters The situation in Yemen Balls of fire and smoke rise from a Houthi-held military camp following alleged Saudi-led airstrikes, in Sana'a, Yemen EPA The situation in Yemen Yemenis search under the rubble of damaged houses following reported Saudi-led coalition air strikes on the outskirts of the Yemeni capital Sanaa Getty Images The situation in Yemen A Yemeni boy looks on as Yemenis search under the rubble of damaged houses following reported Saudi-led coalition air strikes on the outskirts of the Yemeni capital Sanaa Getty The situation in Yemen A Yemeni boy sits amidst the rubble of damaged houses following reported Saudi-led coalition air strikes on the outskirts of the Yemeni capital Sanaa AFP/Getty The situation in Yemen Marine One with US President Donald Trump flies with a decoy and support helicopters to Dover Air Force Base in Dover, Delaware, for the dignified transfer of Navy Seal Chief Petty Officer William 'Ryan' Owens who was killed in Yemen Getty Images The situation in Yemen US President Donald Trump aboard the Marine One to greet the remains of a US military commando killed during a raid on the al Qaeda militant group in southern Yemen on Sunday, at Dover Air Force Base, Delaware, US Reuters

Since the war started in March 2015, the UK Government has approved no less than 194 export licences for arms and related equipment to Saudi Arabia, worth more than £3.3bn (or around 10 times that combined UK-US aid sum). Resisting a sustained chorus of calls to halt arms exports after numerous airstrikes by the Saudis that have violated the laws of war, the UK has repeatedly fallen back on arguments about “assurances” it had received from Riyadh about investigations of more careful targeting.

Similarly, the US sold a record amount of arms to Saudi Arabia under President Obama’s administration, with sales set to continue under President Trump. Earlier this month the State Department approved a resumption in the $300m sale of US-made precision-guided missiles, a deal blocked late in Obama’s administration due to (belated) concerns over civilian casualties.

These arms sales are in contravention of international law. The UK, once a champion of the landmark Arms Trade Treaty (which seeks to stem the flow of weapons that could be used for war crimes and other serious violations), is now acting in brazen violation of it. The UK has ratified the treaty, so it is bound by its rules; and as a signatory, the US must not take any action to undermine its object and purpose, one of which is to reduce human suffering.

With arms being shipped to Riyadh at a furious rate, the civilian death toll has risen quickly. The Office of the UN High Commissioner for Human Rights recently reported that more than 4,600 civilians have been killed and over 8,000 injured in the conflict to date.

To be sure, Houthi opposition forces have killed and injured civilians in Yemen with impunity using imprecise battlefield weapons in residential areas, displaying a total disregard for civilian lives. Such indiscriminate attacks violate the laws of war and may amount to war crimes. At the same time, OHCHR reports that airstrikes have been the “single largest cause of casualties”, with the Saudi-led coalition relentlessly pummelling Yemeni homes, hospitals, factories and funeral halls.

2.1 million children are facing famine in Yemen

Aid with one hand, missiles with the other. Foreign aid from the UK does tremendous good around the world, but in Yemen it’s heavily compromised by the Government’s security-and-trade agenda. Helping rebuild homes and hospitals is clearly very important, but it doesn’t change the fact that the UK or US are complicit in having supplied the bombs used to destroy them.

Here the UK and US are following the dubious lead of Saudi Arabia itself. While heading the military coalition wreaking such havoc in Yemen, the country’s King Salman Centre for Humanitarian Relief and Works, set up in May 2015 in response to the crisis, has spent $576m in Yemen. Amid dire reports of famine and an irreversible humanitarian crisis, last month it pledged a further $10bn. Huge sums. But the context is coated with pitch-black irony.

Last May, evidence was found that British-manufactured cluster munitions had been used by Saudi Arabia in villages in northern Yemen. At the time the UK Government rejected this evidence. Seven months later, Defence Secretary Michael Fallon was telling the House of Commons about an admission from Saudi Arabia that it had used them, but would not do so again. Good enough for the UK Government. The arms sales continued.

Those self-same Yemeni villagers hit by deadly cluster sub-munitions manufactured in the UK (or the US, or Brazil), might – if they’re lucky – receive humanitarian assistance from either London, Washington or Riyadh.

But that’s how things are done in Yemen now. Missiles raining down one day, new kit for a bombed-out hospital the next. Such is the UK’s warped Yemen policy. Meanwhile, Yemen’s charred markets lie abandoned and desolate.

Rasha Mohamed is a Yemen Researcher for Amnesty International