In April 2012, just six months after Colonel Gaddafi had been killed by rebel forces in Sirte, Libya, and as fighting between rival militias continued, an exhibition of British street art opened at the Dar Al Fagi Hassan Art Gallery in Tripoli and then in Benghazi. The works of Banksy and D*Face were shown alongside photographs of graffiti by Libyan artists who had scrawled their messages of dissent furtively on city streets as the uprising against Gaddafi’s regime gathered pace. The show, organized by the Victoria and Albert Museum in London with the support of the British Council, was intended as an act of solidarity with the Libyan people. “I thought it was so important to be there immediately, not to wait. I wanted to say to the Libyans, ‘We are here; you can count on us,’” explains the director of the V&A, Martin Roth.

It was an extraordinary gesture from a museum of decorative arts. Not long ago, our top national art collections were focused primarily on the custodianship of objects in their care, on scholarship and on exhibitions. Today, our museums are also politically engaged, globally connected, and incredibly skilled in the arts of international cultural diplomacy, their reach sometimes extending beyond that of governments.

One institution in particular lies at the heart of this story: the British Museum. Forged in the Enlightenment, expanded through empire, it is now one of the great repositories of world culture. Under the leadership of Neil MacGregor, who took the helm in August 2002, it has carved out a significant role for itself as a global organization with global responsibilities. The policy shift became apparent following the sacking of the National Museum of Iraq. On 12 April 2003, news began to emerge of the systematic looting of the museum, which had been left unprotected as U.S. forces began to take control of Baghdad. Hundreds of people rushed through the galleries smashing glass cabinets to grab objects and attacking sculptures with iron bars before moving on to the building’s vaults. Priceless, irreplaceable works of art disappeared. Statues too heavy to move were decapitated. The destruction was terrible. Three days later, MacGregor held a press conference at the British Museum in London with the U.K.’s then minister of culture, Tessa Jowell. He announced that his institution would take a lead in providing assistance to curators in Iraq and would act as a coordinator for other museums that wanted to help. Soon after that, he dispatched a team of three curators and six conservators to assist museum staff in Baghdad.

The initiative followed a plea for help from curators at the ransacked museum who had long-standing connections with counterparts in London. “When they came under attack, they quite naturally phoned us and asked us, ‘Can you do something?’ ” MacGregor says. “To be part of a global community of people who look after the things from the past is not just about writing articles for learned journals, publishing catalogues, and sharing knowledge. It is about helping each other now.”

Roth shares this view. When we meet, he is just back from a visit to Syrian refugee camps in Lebanon, to which he travelled with the German foreign minister, Frank-Walter Steinmeier. Concerned at reports that ISIS was looting and trafficking antiquities to help fund its activities, Roth spent his time in the camps briefing relief organizations and NGOs on the importance of Syria’s cultural heritage and its history. Accounts have emerged that the terrorist organization is sacking museum collections and seizing objects from ethnic and religious minorities. It is also allowing local people to dig at archaeological sites in exchange for a percentage of the value of any finds, according to a report in the New York Times. “My main purpose is to help to stop, or at least to make more difficult, the way ISIS takes objects out of the country and sells them here on the art market,” says Roth, hinting at plans to set up a joint force of museums to combat this trade.