The North American Soccer League, the former league home of Minnesota United, appears to be gone for good. Its 2018 season was officially canceled this week, a formality that came long after anyone believed the league would survive. The NASL was founded to compete with MLS, as an independent alternative, but like so many upstart leagues before it, it collapsed under the weight of its own ambitions.

Meanwhile, the other lower-division pro soccer league in America — the United Soccer League — is thriving. The USL was near death when the NASL launched in 2010. Since then, though, the league has not only survived, it has grown explosively. USL now has 33 teams and six expansion franchises lined up. It’s officially sanctioned as a second-tier league, replacing the NASL, and is planning to launch a third-division league in 2019.

Where did the USL go right while the NASL went wrong?

The turning point for USL was in 2013, when the league partnered with Major League Soccer. MLS teams either established relationships with existing clubs, a bit like minor-league baseball, or simply moved their own reserve teams to the USL. It gave big-league teams a place to develop players, in a more structured format than the scattershot MLS reserve league, and in the process propped up the remaining independent teams in the USL.

Effectively, the USL worked with MLS, while the NASL, lacking those partnerships, worked against it. Betting against MLS was the wrong move for the NASL, especially since the NASL’s owners didn’t have nearly the resources to make it work. In the end, the NASL was left trying to hoodwink fans with a combination of nostalgia (the New York Cosmos in particular) and promises to be a “real” European-style league rather than the sanitized corporate version presented by MLS.

The sad thing about the death of the NASL is that the league wasn’t necessarily wrong about what American soccer needed.

Though MLS’s stability has been unprecedented in American soccer, its stage-managed, centrally driven approach hasn’t always served the country’s soccer growth well. An independent league such as the NASL, pushing forward without centralized shackles, could have challenged MLS to grow and improve.

Upstart leagues in other sports, such as the ABA in basketball or the WHA in hockey, served as unwelcome catalysts for growth in the more-established NBA and NHL. But the NASL’s bellicose attitude and lack of organizational skills doomed it to be a historical footnote, rather than a legitimate MLS alternative.

It’s telling that four NASL teams have escaped to MLS or the USL, even before the league collapsed. Minnesota, Ottawa, Indy and North Carolina concluded, like the USL as a whole, that working with MLS — not against it — was the only way to survive.

The end of the NASL means the end of any American threats to MLS. Now, MLS and USL are responsible for the growth of American soccer. Here’s hoping they push it forward, despite the lack of outside challenges.

Online: startribune.com/soccer