There's a lot of focus on the Strait of Hormuz right now - the shipping lane as a source of potential conflict - pitting Iran on one side and the U.S. and its Gulf allies on the other.
But in reality this place has been a powder keg going back for decades, and there's a lot of historical precedent for how it could spark.
(SOUNDBITE) (English) UNIDENTIFIED BBC NEWS ANNOUNCER DURING IRAN-IRAQ WAR, SAYING: "(...) anxiety about what Iran has been doing here." So why the Strait of Hormuz?
Why here of all places?
(SOUNDBITE) (English) UNIDENTIFIED BBC NEWS ANNOUNCER DURING IRAN-IRAQ WAR, SAYING: (...) the tankers which carry Iran's precious oil." First of all, this seaway is responsible for about a fifth of all the world's oil exports.
Over 17 million barrels pass through it every day.
Every time an incident happens here oil prices immediately surge.
A major disruption would be a calamity for entire national economies.
OPEC members like Iran, the UAE, the Saudis, and Iraq push most of their crude through it -- and ships are vulnerable.
At its narrowest point the Strait of Hormuz is 21 miles across but the shipping lane itself is only two miles.
It's a chokepoint, and a militarized one.
Iran has at its disposal an array of missile batteries, naval mines, and fast boats on its side of the coast.
On the other side is the Saudi military and also the U.S. Navy.
Its Fifth Fleet is based in Bahrain and is tasked with protecting the waterway.
There's also a lot of history here.
The war between Iran and Iraq in the 1980s specifically targeted each country's oil infrastructure, including shipping.
There was open fighting between Iranian and American vessels here in 1988.
That was also the year a U.S. warship accidentally shot down an Iranian passenger jet killing almost 300 people.
The following decades saw more saber rattling and periodic attacks by militant groups on vessels but, strategically, there are fears that a confrontation here could boil over into something much bigger.
Today the U.S., Saudi Arabia, and Iran are involved in proxy conflicts across the Middle East.
There's a particular concern that, even if the leadership of these countries show restraint, that it might not filter down.
The U.S., for example, doesn't control its allies, particularly hawkish elements in Saudi Arabia or Israel.
Iran may not have control over the militias it backs in Yemen or Iraq, and then there's always human error at any level.
It means that Washington and Tehran could accidentally find themselves pushed into a conflict neither want: a spark that could rapidly expand across the region.