The Iranians reject the latest sanctions:
"The world must know — and it does — that even the harshest political and economic sanctions or other threats are far too weak to coerce the Iranian nation to retreat from their legal and legitimate demands," Iranian Foreign Minister Manouchehr Mottaki told the Security Council after the vote. "Suspension is neither an option nor a solution."
The moderately tougher sanctions include banning Iranian arms exports, and freezing the assets of 28 people and organizations involved in Iran's nuclear and missile programs.
About a third of those are linked to the Revolutionary Guard, an elite military corps.
Another impact may be that the Iranians lash out under pressure, like this:
Iran's top military official, Gen. Ali Reza Afshar, said the sailors and marines were moved to Tehran and under interrogation "confessed to illegal entry" and an "aggression into the Islamic Republic of Iran's waters." Afshar did not say what would happen to the sailors.
Iranian Foreign Ministry spokesman Mohammad Ali Hosseini accused the British of "violating the sovereign boundaries" of Iran, calling the entry a "blatant aggression."
This move hurts the ability of Iran's defenders to just portray the Iranians as poor victims. Why do it?
During the Iran-Iraq War, the Iranians successfully ignored the world essential siding with the Iraqis against Iran. The mullahs did not make a bad situation worse by lashing out. For a while. Eventually, the Iranians fired (with missiles, small boats, and mines) at Western oil shipments, provoking the entry of Western navies into the Gulf to protect that traffic. And that led to the clashes between the Iranians and the US Navy that demonstrated our absolute naval superiority.
So if this additional amount of pressure leads the Iranians to decide to attack us, we must take advantage of the ensuing fight to cripple the Iranian nuclear program and regime pillars.
The Iranians will be angry regardless of how limited the fight is. They may reply to a limited military response by escalating anyway as they've threatened. So let's just hit them as hard as we can.