Here's one way to phrase those interests - an effective Ukrainian defense against Russian aggression raises the cost of that aggression and (crucially) raises the perceived cost of future aggression.

我们可以这样理解这些利害——乌克兰对俄罗斯侵略的有效防御会提高俄方侵略的成本，也会无形之中提高俄方未来侵略的感知成本。