At a time when the extraterrestrial Dire Wraiths became a matter of international concern, most costumed super-teams headquartered in the United States could not be reached for help. At the bottom of an image of the missing heroes (Rom #53), a footnote asked readers to turn to the Secret Wars limited series for details.
But not all of the heroes pictured as missing actually participated in the Secret Wars. The New Defenders, rather, were in the clutches of the Secret Empire while numerous other heroes were away during Secret Wars.
The same issue the New Defenders escaped from the Secret Empire, interestingly enough, they received official government clearance as a super-team (New Defenders #130). One can only imagine how the inability to reach the Fantastic Four, the Avengers, and the X-Men during a crisis time of might have factored into this decision.