Not only is this not relevant to the question...
It kind of is (or rather would be under different circumstances). The prospect of winning a case surely is part of the motivation to file it. Then when you file a case and are asked why you do that, you might want to say that you are convinced that you are going to win it.
In this case however, Nicaragua doesn't seem to have said so and the author would have a hard time using his/her opinion about the low success rate as a motivation. If anything it would be the opposite, a reason not to file.
On the political stage, actors might even be motivated to file cases if they do not expect them to win, just for the publicity. Might even be the case here. Maybe that is what the author meant. In that case, a statement about the low success probability would be helpful, but without inside information rather speculative.
It's a tangent that is vaguely related but in no way backed up (by similar cases, by what Nicaragua said itself, ...). So rather not useful. Edits against the will of the original author are a bit problematic too, so rather just downvote and move on. The "Very low quality" flag is a bazooka and can be misused. I wouldn't use it here, but your mileage may vary.