Indonesia’s new trade minister found a good example of the dangers of protectionism in an unlikely place: the armor-plated car of the country’s president. Officials had trouble bringing in the bulletproof tires needed for President Joko Widodo’s vehicle because of import restrictions passed by the trade and industry ministries in July. Minister Tom Lembong took over the trade portfolio in August and this week revoked the rule, which was also disrupting the mining and aircraft industries.