It's primarily because of the time in which the film is set. You have to remember, this is still in a timeframe where the Cold War was on. It was shortly after the film's release (in August) that the Berlin Wall fell (which was in November 1989). Hell, it basically about how the Cold War is pointless (especially with the Special Edition, where Bud's message basically points that out). Coffey, the captain of the sub, Coffey's Superiors... They're all a part of the Cold War, and they see everything as Russian (as pointed out by Lindsay). There have been times where Russians have been scared off by the actions of Americans just showing up, just as much as there have been times where Americans have been scared off by Russians showing up during this period of time, mostly because neither side wanted to escalate the conflict (this is reflected in many other films from that timeframe. In fact, Steve De Jarnatt, when it came to his film Miracle Mile (1989), has said he could have made the film sooner in the 1970s or early 1980s, but every studio that was approached with the script didn't want to have the Americans to be the ones to fire the first shot, which was how it was written in the story. More often than not, in most of the stories, it's often the other side escalating or firing the first start, not the home side). Was the captain reckless? Yes. That's because he was being vigilant, and it's that vigilance that got him and the others on board killed. If there had been no Cold War going on, then he and them would still be alive (as well as Coffey and a large bulk of the Rig's crew would also be alive). It's not the first time that Cameron made a war analogy in his films (I mean, just look at Aliens, which he has flat out stated was inspired by the Vietnam War on more than one occasion).