From luxury French perfumes such as Chanel No. 5 and Yves Saint Laurent’s Opium to the humble incense stick, from traditional Chinese medicine to modern pharmaceuticals, and from Hindu and Buddhist religious carvings to fine furniture, there is a common ingredient — sandalwood. For thousands of years, richly scented sandalwood has been traded across Asia, the Middle East and Europe. Caravans from India carried its precious heartwood and oil to ancient Egypt, Greece and Rome. Today, the sandalwood trade spans the world, but a guaranteed supply is a big issue.