There are precedents for what Iran's "Supreme Leader" Ayatollah Ali Khamenei has just done.  Khamenei is at the top in Tehran, and he is threatening to wipe Israel off the map.  Khamenei said that "the fake Zionist (regime) will disappear from the landscape of geography."  He said this to a meeting of Iran-Iraq war veterans.  That 1980s war claimed millions of lives...and it was fought for what?  Both Saddam Hussein of Iraq and the mullahs of Iran showed a complete disregard for human lives in that pointless, brutal, and inconclusive decade-long struggle. 

One of the most horrific aspects to that war was the little plastic keys the clerics gave to thousands of Iranian boys as young as 10.  These keys on necklaces would, they told those doomed lads, open up the gates of Paradise to them.  Then they sent these children to clear Iraqi minefields -- by marching right through them.  What else do we need to know about the inhumanity of this regime?  These are the mullahs who invented suicide bombing.  They sent a Hezb'allah driver and truck into the midst of the U.S. Marine barracks in Beirut, setting off a blast that killed the driver and 241 U.S. Marines and Navy Corpsmen, in 1983. 

Now, Khamenei is once again making threats of annihilation against Israel.  These threats eerily echo those made by Egyptian dictator Gamal Abdel Nasser in the days that led up to the 1967 Mideast War.  Nasser kicked U.N. truce supervisors out of the Sinai desert, thus making possible a sneak attack on Israel.  He then proceeded to close off the Gulf of Aqaba, preventing Israel from using the port of Eilat.  He knew the risk he was taking in thus provoking war with Israel.  He wanted that war.  Nasser said: "We knew that by closing the Gulf of Aqaba it might mean war with Israel. [If war comes,] it will be total and the objective will be to destroy Israel" (Washington Post, May 27, 1967).

Nasser sought to unite all the Arabs -- but not behind Islam, for he was a secular dictator, an "Arab socialist" bent on creating pan-Arab unity by demonizing the Jews.  He blamed the Jews of Israel for the backwardness and poverty of people on the "Arab street."  It is the oldest of dictators' ploys.  If your corrupt and debilitating regimes produce dangerous pressures from below, blame it all on the Jews.

Nasser took to the radio and called upon all Arabs to "drive the Jews into the sea."  Israel was not eager for war, especially not a war on four fronts.  Israel in 1967 was just nine miles wide at the widest point.  The Jewish state was dangerously exposed to invasion. 

And, too, there were the Soviets to consider.  The Lyndon Johnson administration was then thoroughly bogged down in a war in Vietnam.  They worried that an Israeli strike against threatening Arab regimes might escalate into World War III, with the USSR intervening to support its Arab clients in the region.  There was no support from LBJ's White House for an Israeli armed response to the murderous threats coming from Arab capital.  Then, as now, the word from the politically worried administration in Washington to the Israelis was: cool it.

Easy for you to say, Mr. Johnson.  Easy for you, too, Mr. Obama. 

The Israelis have patiently endured threat after threat of being wiped out by eliminationist neighbors.  They have warned the U.N., the world community, and especially the Obama administration that there is a limit to their endurance. 

The Obama administration's response has been to trumpet the success of its latest round of economic sanctions against the Tehran regime.  Yes, sanctions might indeed "bite"; they may have a "crippling" effect on the Iranian economy.  But all those sanctions do is make the wretched people of Iran more wretched.  And, in a perverse way, they serve to prop up the mullahs' regime.  They can blame all their people's misery on the U.S. sanctions and say it's all the fault of the Great Satan.

Remember those plastic keys.  The kind of men who would send children to their deaths are not the kind of people who care about the suffering they cause.  Sanctions may bite, but they don't bite the mullahs.

Israel often appears in the world press as a naysayer.  When the doves of the U.N. are cooing, when there are handshakes on the South Lawn of the White House, when the Spirit of Camp David Accords wafts gently in the breeze, hard-headed Israeli analysts question whether these moves have really defanged terrorists or just given them some dental hygiene.

Prime Minister Menachem Begin was once confronted in Washington by a public relations executive who appealed to him to try to put the Israeli case in more positive terms.  "You always seem to be saying no," the friendly critic charged.  "Please try to put the case for Israel in more positive terms. It means a lot in public relations, I can assure you."

The prime minister responded with a courtly bow.  He thanked the executive for his support for the Jewish state.  He said he and his colleagues in the Knesset -- the elected Knesset, he emphasized -- would consider ways to be more positive.

"But, Mr. Public Relations executive, I hope you will grant me this: In our part of the world, there are certain precedents for Thou Shalt Not."

There are indeed certain precedents for Thou Shalt Not.  Including Thou Shalt Not Murder.  And an Iranian cleric who daily incites his captive people to slaughter the Israelis has violated that ancient Thou Shalt Not.

That is why the Israelis now have their Casus Belli, their just cause for war.  If they strike Iran's still-spinning centrifuges and stop their headlong quest for atomic weapons, they will be well justified.

Americans should thank, not criticize, Israel if Israelis defend themselves.  They'll be defending us, too.  They may be fighting by themselves alone, but they do not fight for themselves alone.

Ken Blackwell and Bob Morrison are senior fellows at the Family Research Council.  Mr. Blackwell was the U.S. ambassador to U.N. Rights Commission, 1991-93.