North Korea's successful test of its first intercontinental ballistic missile carries grave geopolitical implications for a vast swath of the world. Although such an achievement seemed improbable not long ago, it was all but inevitable.

The Hermit Kingdom tested its first nuclear bomb in 2006 and has spent the past decade steadily improving the rockets needed to lob one at its enemies. Its missile program proceeded deliberately at first, but ramped up significantly under the leadership of Kim Jong-un. Despite its frequent missteps, experts agree that North Korea will achieve the ability to launch a nuclear missile.

Few people who watch the country's weapons program expressed surprise at Tuesday's test of a Hwasong-14 missile, which went 580 miles and reached an altitude of 1,741 miles during a 37-minute flight.

"I wouldn’t call the test over the weekend a surprise simply because they do have a stated goal of creating an intercontinental range ballistic missile," says Michael Elleman, a senior fellow for missile defense at the International Institute for Strategic Studies and an analyst for the North Korean watchdog group 38 North. "This is part of a longstanding process and I expect to see more tests."

The Trump administration confirmed that North Korea launched an ICBM. US and South Korean forces performed a joint ballistic missile test on Wednesday in the Sea of Japan---a response at odds with China and Russia, who called for deescalation and peace talks. North Korea, meanwhile, reiterated its goal of developing nuclear weapons and the missiles to fire them anywhere in the world.

Tuesday's test followed a series of failed launches---the most recent in April---and North Korea touted it as proof of its commitment to achieving that goal.

North Korea's government-run Korean Central News Agency said the test showcased the missile’s propulsive phases and durability during re-entry. The North Koreans fired the missile at an exceedingly steep trajectory, but experts said its altitude, distance, and flight time leads them to believe the Hwasong-14 could have a range of 4,039 miles or more. That places much of Alaska at risk, along with US allies like Japan and targets as far away as Moscow.

Still, experts caution against making broad generalizations about the country's missile program based upon one test. Missile testing is an iterative process with each successive test building on the last as scientists and engineers improve each component.

Tracking North Korean missile development poses a particular challenge. The country had shown off the Hwasong-14 missile in military parades before Tuesday's test, but the Pentagon said on Wednesday that the missile was one "we've not seen before," indicating that North Korean engineers have adapted it since that public display.

Experts pore over images released by North Korean state media to glean the smallest details about the country's capabilities, but many aspects of a missile test aren't knowable from afar. Analysts cannot determine how much weight the missile carried, for example, how it handled reentry into the atmosphere, whether it was launched with a particular target in mind, and whether it actually reached that target. This makes it difficult to contextualize the missile's actual capabilities.

Experts also note that since North Korean missiles land in many locations, it's unlikely that the country has sensor arrays collecting data about the final stages of flight. This would be valuable information for development that the country doesn't seem to gather at this point.

"You can observe the success of a missile flight, but it's harder to observe the success of a reentry vehicle or the miniaturization of a weapon other than what North Korea claims—unless they conduct an actual nuclear missile test," says Frank Aum, a former Department of Defense senior advisor on North Korea. "Until they do something like that we’ll never know for sure."