When Iranian missiles struck the Pearl gas-to-liquids facility in Qatar, they knocked out one of Shell’s crown jewels, a giant plant that is among the most sophisticated and profitable businesses in the company’s sprawling global operations. The plant was so heavily damaged that one of its two production lines is expected to be shut for at least a year, Qatar said. Some of the Western oil industry’s most important investments have become targets for Iran in its war with the U.S. and Israel. Exxon Mobil, which has more at stake in Qatar than any other big oil company, gets roughly…