Why would you think Iran's leaders are suicidal?
Likely because they think Iran will be (is) attacking back a greater military power that will strike back excessively. They see it as futile attempt that will only give the US more reason to start a war. An important fact here, though, is that there are no American deaths. Important for the US and for Trump. If there were, that would be enough for Trump to retaliate strongly, bringing us into full blown war and the eventual death of Iran's government, which the Iranians certainly do not want.
Looking from Iran's perspective, they don't want war, but they can't let a high ranking military commander's assassination go without hitting back. It's a calculated risk, just like it was with Trump starting this shit in the first place. The best case scenario is that there will be no further attacks, or very limited attacks...beWe can all hope that happens, but I personally don't see it. Trump has the ball in his court now, so yeah...
If I'm Trump, I'd listen to the person telling him that so far this retaliation is "nothing" and that if the price to pay for the murder of Iran's general is a few Iraqi deaths, that would be a damn good deal for any president to take right now. That, compared to the casualties that a long, miserable war would bring, is a massive difference. It's already fucked that Iraqi soldiers died for this shit and Trump's sensibilities for the kind of deescalation that must happen and happen quickly, doesn't give me any hope.
Without a full explanation/competent defense for the assassination by the US, it's really difficult to predict what Trump/US are thinking. What it looks like is that there is no coherent plan and that Trump already has blood on his hands for Iraqi's casualties and likely the deaths of many more coming.
The only thing that gives me hope is that Trump knows a war is something he definitely would want to deal with...but he's also desperate for a second term...Frightening times for the innocent people that Trump has forced in this mess. I wish I had better words, but stay safe.