Professor Marc Weller, a leading expert in international law in the University’s Politics and International Studies department, has claimed that the US military operation against Venezuelan president Nicolás Maduro was a fundamental breach of international law.

In a video published on the University’s YouTube channel on Wednesday (07/01), four days after the capture of President Maduro, the law professor contended that the US operation constitutes an unlawful use of force that breaches Venezuelan sovereignty and has no credible legal basis under the UN Charter.

Professor Weller stated: “The US operation in relation to Venezuela is clearly internationally unlawful, and it will be very important for the international community to identify it as an unlawful operation and to identify the US as a violator.”

Weller, a fellow of Hughes Hall, is the former director of Cambridge’s Lauterpacht Centre for International Law. He has been an adviser in many international peace negotiations, and is renowned as a mediator in international disputes. He took part in the drafting of the Kosovo Constitution, in addition to drafting the Yemen peace agreement.

In the video, Weller rejected the possibility that the capture of Maduro was an act of pro-democratic intervention or law enforcement, arguing that the US “have not disguised in any way” that this operation was instead motivated by their interest in Venezuelan oil.

“The US argues that it can now take over the oil sector in Venezuela, the richest oil deposits in the world,” he warned. “And rather than having some sort of subterfuge explanation, such as democracy or self-defence, they are saying quite clearly, yes, that’s what we are hoping to do. And that is entirely unprecedented.”

Weller emphasised that there have been “no steps taken to assist the democratic opposition to come to power or to have fresh elections rapidly”. Instead, “the US is dealing with the government which it purports to have replaced,” given that it “presumably believes that [this] government, under the threat of the further use of force, will deliver […] the demands the US has made in relation to oil”.

The professor added that there is no legitimate case for self-defence. He dismissed the argument that protecting the American people from the effects of drug trafficking could justify the use of force, explaining: “Self-defence requires, under the UN Charter, an armed attack against the state […] Obviously, drug trafficking is very far removed from that.”

He condemned the US-imposed naval blockade of Venezuelan oil shipments enacted last December (16/12), calling it “unlawful” and “a war-like act”.

Weller also raised concerns that leaving existing Venezuelan power structures largely intact could provoke internal conflict. He asserted that the intervention “has only removed the head of the snake, but the snake still wiggles,” with the government now moving to repress the population in order to retain power.

The international prohibition of the use of force, according to Weller, is the “greatest civilisational achievement of mankind over the last 100,000 years”. Ignoring this principle, as the US has done, he argued, sets a dangerous precedent.

The academic warned that “we are at risk of returning to an international order of the 19th century,” when powerful states used force with impunity to seize resources.

He continued: “How can we oppose the use of force by the Russian Federation in Ukraine if, at the same time, we accept it once undertaken by the US in other places? The essence of international law is that the same legal rules apply to all.”

Weller stressed that the international community must unequivocally recognise the US operation as unlawful, describing the disunity among European states in the UN Security Council as “disappointing”. He contrasted condemnations from Denmark and Spain with what he described as the UK’s “odd approach,” which acknowledged Maduro as “a very bad person” but stopped short of condemning the US action.

Discussing the broader implications, he stated: “There will now be a debate whether this episode, even more than the unlawful invasion of Iraq in 2003, changes the international system as a whole.” Weller predicted that the world may be shifting toward an international system dominated by regional great powers – principally the US, Russia, and China – each asserting control over their own spheres of influence, including through the use of force.