An interesting if unintentional consequence of potential disruption of the oil supply from Iran, either by sanction or (hopefully not) military action: Sri Lanka may really be hit hard.
As Reuters reminds us, Sri Lanka is nearly entirely dependent on Iran for its oil imports. While its overall imports of oil are lower than those of China, India, and Japan—Iran's largest oil customers—these nations also import oil from plenty of other places as as well, so on a percentage basis, it's far less of a challenge to switch suppliers.
Also potentially pinching Sri Lanka is the fact that the nation's only oil refinery is specifically tweaked to handle Iranian oil, which has a higher sulphur content and is of different density than oil from other places.
Read more, for Sri Lanka's options.