Chewing gum causes problems in Singapore, apparently much bigger problems than elsewhere.
In 1983 a gum ban was proposed because of problems in public housing. Vandals stuffed used gum in mailboxes, inside keyholes and on elevator buttons. Chewing gum left on floors, stairways and pavements increased the cost of cleaning and damaged cleaning equipment. Gum stuck on the seats of public buses annoyed passengers.
Government leaders thought that a ban would be too drastic and did not take immediate action. In 1987, the Mass Rapid Transit (MRT) system, began operation. It was then the largest public project ever implemented in Singapore, and expectations were high. Vandals stuck gum on the door sensors, preventing the doors from functioning properly and causing disruption of train service. In 1992, new Prime Minister Goh Chok Tong decided on a ban.
The import of chewing gum was immediately halted. A transition period was provided for stores to sell their their existing inventory, and then the sale was completely terminated. When first introduced, the ban caused controversy and some open defiance. Some people went to nearby Malaysia to buy gum. A few tried to bring back more than what is legally permitted. These offenders were publicly "named and shamed" to deter other would-be smugglers. As time passed and the uproar died down, Singaporeans became accustomed to the lack of chewing gum. There was no black market.
In the mid 1990s, Singapore’s forbidding laws began to receive intense international attention. The US media sensationalized the case of Michael P. Fay, an American teenager sentenced to caning for vandalism (spray paint, not chewing gum). At this time Singapore gained its infamous "nanny state" image, with actions of every citizen scrutinized and dictated by the government.
Singapore leaders responded that as a sovereign state, Singapore had the right to form policies based on its unique political and cultural values, and these policies result in greater overall benefits. When a BBC reporter suggested that overly draconian laws would stifle the people's creativity, an official retorted: "If you can't think because you can't chew, try a banana."
In 1999, US President Bill Clinton and Singapore Prime Minister Goh Chok Tong agreed to initiate talks for bilateral free trade. The talks continued during the Bush administration. By the final phase of negotiations in early 2003, there remained two sticky issues: the War in Iraq and chewing gum.
US officials requested that Singapore express support for US invasion of Iraq, which was readily agreed to. The US also demanded that Singapore lift the gum ban, because of lobbying for the Wrigley gum company. This caused a serious dilemma to Singapore leaders. They knew that the agreement would be a great boost to Singapore's economy and they could not afford to be delayed by the chewing gum issue; but giving in would make them look bad.
Singapore came up with a creative solution. They recognized the health benefits of certain gums, such as Wrigley's Orbit sugar-free gum that contains calcium lactate to strengthen tooth enamel, and Pfizer's smoke-stopping Nicorette gum. They allowed sales of these medicinal gums, by dentists and pharmacists, who record the names of buyers. (info from BBC and Wikipedia)