Even though most diplomats are law-abiding, it's the high-profile avoidance of laws that gets the greatest attention. In New York City, for example, diplomats from Angola to Zimbabwe owe the city more than US$18 million ($24.9 million) in unpaid parking fines.
Even for New York it's serious money, yet there's little the city can do to collect the fines regardless of whether the illegally parked cars were on diplomatic business or not.
While parking fines may seem minor, diplomatic immunity covers more serious situations too.
United Kingdom's Foreign Office Minister Kim Howells revealed in 2007 that diplomats in London had avoided prosecution for rape and even for indecent assault on an 11-year-old girl. An intoxicated Georgian diplomat who was in a traffic accident that killed a girl in Washington DC in 1997 claimed diplomatic immunity, and was only prosecuted after the Georgian government waived his immunity.
While claiming diplomatic immunity to avoid prosecution may seem unfair, the principles behind it are fundamentally sound.
Why it's needed
Diplomatic immunity enables the representatives of a country to do their work without fear of imprisonment or retribution.
In some regimes, this means that diplomats can meet freely with opposition party members, watch a demonstration or pick up commercial information without fear of being arrested. Although they can be expelled from a country for violating its laws, they can't be prosecuted.
This is crucial in countries with ambiguous legal practices, where people might be jailed for minor infractions or none at all.
Immunity enables diplomats to do their jobs.
While laws providing immunity go back at least as far as 18th-century England, it's the 1961 Vienna Convention on Diplomatic Relations that establishes today's rules. Section 29 says "the person of a diplomatic agent shall be inviolable. He shall not be liable to any form of arrest or detention". Expanding further, Section 31 says that "a diplomatic agent shall enjoy immunity from the criminal jurisdiction of the receiving State. He shall also enjoy immunity from its civil and administrative jurisdiction".
Even though Section 41 says "it is the duty of all persons enjoying such privileges and immunities to respect the laws and regulations of the receiving State", immunity usually takes precedence. On or off the job, accredited diplomats enjoy immunity.
Singapore's diplomats, too, need this immunity to do their job well.
In countries where the most innocuous commercial information can be classified as a state secret or where meeting opposition politicians or newspaper reporters who are unpopular could land you in jail, diplomats can still gather information and meet key sources without fear of arrest.
On duty or off duty, Singapore's diplomats and their families are protected.
For diplomatic immunity to work, it requires reciprocal respect by both sides. If one country arrests or prosecutes a diplomat who is supposed to have immunity, then that country's own diplomats could become subject to the same tit-for-tat treatment overseas.
Singapore can ask another country to waive immunity for a diplomat, but can only prosecute him or her only if that country agrees.
When diplomats arrive home, of course, it's a different matter and they're subject to their own country's laws.
Diplomats who travel back to the country of their posting after their official duties end are also subject to local laws, like everyone else.
No matter how much we may disagree with or dislike the manner in which immunity protects diplomats in some situations, it's a critical principle for effective relations between countries.
While ignoring immunity sometimes might seem preferable at first glance, it's a two-way street that needs to be respected all the time to protect Singapore's diplomats overseas. Only by following the principles of the Vienna Convention at home can one country expect others to do the same for its diplomats abroad.
The writer is a former diplomat.
He is currently a consultant who has lived in Singapore since 1992.