WASHINGTON -- Despite a US-Iran memorandum that opened a 60-day diplomatic window, missile exchanges and maritime threats suggest the negotiations are faltering under growing military pressure.RFE/RL spoke with Hudson Institute Senior Fellow Mary Kissel about whether diplomacy can still deliver lasting security, and why she believes Iran's nuclear ambitions remains the central issue.RFE/RL: We're seeing missile exchanges, maritime incidents, and renewed threats in the Strait of Hormuz. Does this suggest the negotiations are already being tested?Mary Kissel: Yes, it does. I think that's fairly clear, and it's consistent with what we've observed from the regime not just over the past few months of this current conflict, but over the past 40-plus years. It's entirely consistent, and in that way they're a lot like Communist China -- they will test you until you decide to push back and force them to stop.RFE/RL: Are both sides still committed to preserving diplomacy, or have recent military developments fundamentally complicated that effort?Kissel: You always have to ask: What's the point of a diplomatic process? Is it simply to show that you're talking, or is it really to achieve your strategic goals?The United States' strategic goal is very clear. This regime has killed thousands of Americans, not to mention tens of thousands of its own people, and it wants nuclear weapons. We've already seen what it's capable of without them -- striking civilian facilities in the Gulf, threatening [the] Diego Garcia [military base], and developing ballistic missiles capable of reaching even the United Kingdom.