Even before news broke in April that Mitsubishi Motors had been playing fast and loose with Japanese regulators over fuel economy tests, the company had been struggling to compete in its domestic market and was on life support here in the US. Nissan, on the other hand, has been doing quite well, and on Thursday it announced that the two companies will form a strategic alliance, sharing platforms, technology, and administration. Nissan will also buy 34 percent of Mitsubishi Motors for $2.2 billion (¥237 billion), paid for with profits that are up 14 percent year-on-year.

At ¥487 a share, Mitsubishi is quite the bargain. The company was worth twice that in early April before the efficiency testing bombshell dropped. A bombshell that happened to be dropped by Nissan, as it happened; the affected vehicles are the results of a collaboration between the two OEMs. (Over at Jalopnik they're wondering if this hasn't all been a little too convenient for Nissan.)

This won't be the first such strategic alliance for Nissan. It's been joined up with French automaker Renault since 1999, and both companies (as well as the Renault-Nissan Alliance) are run by the same CEO, Carlos Ghosn. Other brands in the alliance include Infiniti, Dacia—as in James May's favorite, the Sandero—Datsun, and Lada.

"This is a breakthrough transaction and a win-win for both Nissan and Mitsubishi Motors. It creates a dynamic new force in the automotive industry that will cooperate intensively, and generate sizeable synergies," Ghosn said in a statement. "We will be the largest shareholder of MMC, respecting their brand, their history and boosting their growth prospects."

It's easy to see how Mitsubishi benefits from this alliance. Nissan is an industry leader in electrification. Plus, the company has a strong presence in the US. It's a little harder to see Nissan's motivation. Nissan apparently hopes to benefit from Mitsubishi's relative strength in Southeast Asia.

And it does make the Renault-Nissan Alliance one of the biggest global carmakers out there—in 2015 its combined output (including Mitsubishi) was 9.6 million vehicles, almost rivaling the big three of Toyota, General Motors, and Volkswagen.