One question surrounding the North Korean ship that was stopped in Panama, which  found it to be illegally transporting military components after leaving Cuba, is whether this equipment is laughably obsolete or something more serious. On the surface, it would certainly seem to be the former. As one anonymous official told the New York Times, "When this stuff was new, Castro was plotting revolutions."

Firm conclusions would be, at this point, impossible. We don't yet know for sure what was even on the ship, much less what it was being used for. So far, all we have to go on are a few photos released by the Panamanian government and a statement by the Cuban foreign ministry, which seem to contradict one another. But based on the currently available information, the most plausible (though far from only) theory would seem to be that North Korea was planning to upgrade the outdated surface-to-air missile technology and then resell it.

The strongest datapoint we have to go on is a single photo and brief video clip (above) of the equipment being smuggled aboard the North Korean ship, which was broadcast by, of all things, the official Twitter account for Panama's president. The images show large, angular, olive-colored metal objects. Defense consulting firm IHS Jane's quickly released a statement asserting that the components appeared to be a very old model of fire-control radar for surface-to-air missiles.

Panama's president examines military equipment found hidden on a North Korean ship. (Still from AP video)

Specifically, Jane's said, it appears to be a RSN-75 "Fan Song" radar for the SA-2 surface-to-air missiles. Other analysts have since said the same thing; one suggested that it was, more specifically, the SRN-75M3 Fan Song E Variant, the latest in that series. You can see pictures of the fully deployed RSN-75 here: It certainly does seem to resemble the object on the North Korean ship. I can't post the photo because it's copyrighted, but there's a handy annotated image of the system here.

Here's the deal with the RSN-75 Fan Song: Yes, it's very old, but it may also be upgradable and is still in use in much of the world. According to an extremely in-depth analysis and history of the RSN-75 and SA-2 by military analyst Paul O'Connor, it made up "the backbone of the Soviet/Warsaw Pact air defense system constructed during the Cold War era" and was "exported to almost every Soviet client during the Cold War." That includes, of course, Cuba and North Korea. The way it works is that the RSN-75 radar system goes in the center of a cluster of SA-2 missile batteries, which it helps to aim and coordinate. Here, via O'Connor, is what he calls a typical Fan Song system set-up, this one in Yemen:

A typical Fan Song missile defense system, this one in Yemen. (Google Earth/Paul O'Connor)

O'Connor also finds a surface-to-air missile layout in North Korea. Here's the thing: it uses the RSN-125 radar, which is more advanced than the RSN-75 that North Korea was caught moving around.

A surface-to-air missile system in North Korea. (Google Earth/Paul O'Connor)

Two big questions here are: (1) Why would North Korea want to import, at some risk, an RNS-75 radar when it likely already has many of its own? (2) Why bother to move around the system at all, which is decades old and outdated beyond being of much use?

The most plausible theory that analysts are throwing around would be that North Korea is seeking to upgrade the system for another country, most likely Cuba. One former analyst with the U.S. National-Geospatial Intelligence Agency, which does lots of satellite analysis of military installations, notes that Belarus has developed a capability to upgrade the system to something more modern. North Korea, which has a substantial domestic military production industry, may well have developed a similar capability and could have been planning to upgrade the RNS-75 and whatever else was on board, then to ship it back to Cuba.

Cuba's official foreign ministry statement sort of backs up this theory. The statement admits that the North Korean ship "transported 240 metric tons of obsolete defensive weapons" (although it does not list the SA-2 Fan Song system) and says this was to be "repaired and returned to Cuba." It's an odd admission, given that this violates international sanctions against military trade with North Korea. Even more puzzling is the fact that this provocative and defense-oriented move came at a time Cuba's government is tepidly moving toward thawing ties with the United States, a goal that would not be served by upgrading military equipment with North Korean help.

As a caveat, though, an official who works on Cuban matters explained to me recently that the Cuban government is more internally divided on rapprochement than it can sometimes seem from the outside. It's possible, then, that someone in Havana still holds to the old line of resistance against U.S. imperialism and wanted to upgrade accordingly.

Another possibility some analysts have raised is that there might be a third country involved, either as the initial source of the equipment or its ultimate destination. The Washington Post's Billy Kenber reported that this particular ship has spent some time visiting Bangladesh, Pakistan and Iran. North Korea's military program is one of its few sources of export revenue, illegal though it may be. To be clear, though, the prospect of another country's involvement is pure speculation at this point.

In all, we're left with at least three questions about the incident:

(1) Was the equipment originally from Cuba or somewhere else?

(2) Was North Korea the equipment's final destination or was it just to be upgraded there and shipped back out?

(3) If North Korea was planning on upgrading and reselling the equipment, was it going back to Cuba or somewhere else?

Ultimately, the story does not so far appear to change our understanding much.