It doesn't take much to realize that there is a degree of probability that North Korea will attack South Korea using nuclear weapons in the future. China does not control North Korea, and Russia could benefit in the future if both North Korea and Iran acted out its own hostilities. Thus, Israel would be forced to defend itself. My only real question is whether Iran (after developing nuclear weapons) will content itself with an attack on Israel or will it strike out at its Great Satan, the United States?
Note: The Korean War never ended. Only a ceasefire was agreed upon.
Note: Iran has repeatedly vowed to destroy Israel at all costs. This yields them political allies in many places.