Is it the case that Iran wants to join the nuclear club to gain safety through power because other nations will fear attacking them, but not to launch a nuclear attack on Israel or the US?

Here you are seeing the truth of things apart from the heavy layer of propaganda and bias maintaining a steady drumbeat of Iran bashing, which portrays them as terrorist zealots. Their militaristic bluster and sympathy for terrorism as a strategy to foment trouble throughout the Middle East is to effect a softening up and to keep the cause of Islam, as they see it, in the consciousness of everyone. So it is done to get attention and to keep the agenda of wanting to attain supremacy in their religious views alive and well. But they are wanting to go about it cleverly and not simply put their heads on the chopping block to be martyrs.