It's an old phenomenon: When the dispossessed get clout, the past becomes a battleground. Often the stakes in the present are extraordinarily high.

An exemplary skirmish over very bad history is taking place in the U.S. Congress -- in this case, the World War I slaughter of Armenians by Ottoman Turkey.

Whether or not the Ottomans' mass deportation and murder of Armenians in 1915 and 1916 reaches the formulaic, industrial magnitude of the Nazis' genocide or Stalin's decimation of Ukraine is a debating point for lawyers and apologists. The Ottoman "Young Turk" government took a systematic approach that stinks of classic tribal "ethnic cleansing." The Ottomans disarmed Armenian soldiers and removed them from the ranks of the Turkish army. Suspect loyalty and connivance with the Orthodox Christian enemy, Russia, was the ostensible rationale.

After confiscating Armenian guns, Ottoman knives appeared. Mobs murdered Armenian intellectuals and leaders -- killing communicators silences a community. Then the deportations began, featuring long marches where starvation and sunstroke killed as many as the attacks of "thieves and raiders." One-and-a-half million Armenians (out of a population of approximately 2.5 million) died in this directed chaos. Darfur and the Congo are contemporary examples of this hideous technique.

WWI ended. After a bout of internal chaos and a war with Greece, republican Turkey emerged from the Ottoman wreckage. Its political architect, Mustafa Kemal Ataturk, launched political and cultural revolutions, creating a secular Turkey and with it a possible Islamic bridge to modernity. Turkey adopted Latin script, a visual, literary break with the Ottoman Empire and caliphate. It's one reason al-Qaida fanatics despise Ataturk more than they do George Bush.

Modern Turks can make a case they aren't the Ottomans.

Diaspora Armenians, however, now have influence and a voice. The once dispossessed have earned it. Armenians have had extraordinary political and economic success in Western Europe and the United States.

Only the heartless would dismiss their desire to recognize the great wrong. Yet historical verification and vindication aren't the only goals -- the U.S. House resolution backed by Armenian-Americans demands punishment of the perpetrators.

The perpetrators, however, are long dead. The Turkish government thus sees the resolution as a political attack on Turkey.

At a less volatile moment one can imagine Congress passing the nonbinding resolution. I would support it, particularly if it promoted Turkish and Armenian reconciliation.

But find the less volatile moment. The Clinton administration judged the year 2000 as too volatile to pass the House resolution. President Clinton valued U.S.-Turkish relations, and the United States needed access to Turkish airbases to enforce the U.N.-mandated northern no-fly zone that helped protect Iraqi Kurds from Saddam. Clinton got then-House Speaker Dennis Hastert to kill the resolution.

Those Turkish bases now supply and support U.S. troops in Iraq. No matter one's opinion on Iraq, antagonizing Turkey when it provides air and logistical bases supporting U.S. troops actively deployed in a combat zone is foolish and craven. A Turkish decision to shut down these facilities would cut a major coalition supply line. U.S. troops in Iraq would face increased risks.

This is reason enough to delay passing the resolution. There are others. For two years, Turkey has threatened to invade northern Iraq in order to destroy Kurdistan Workers Party (PKK) bases. The Iraqi government and Washington have both promised Turkey they will "act against the PKK." Turkey says it is tired of waiting -- and has an army on the Iraqi border prepped for action.

Cynics suggest Turkey has been waiting for an opportunity to slip U.S. calls for military restraint and launch a decisive attack to finish off the PKK. The resolution provides Ankara with just this opportunity. Conceivably, Washington could "trade" a deferred resolution for a Turkish promise to restrict its operations in Iraq to "hot pursuit" situations, special-forces actions and surveillance. Diplomats on both sides might structure such a transparent but useful give and take.

Note I said deferred resolution. 2015 may be as volatile as 2007. Historical horrors like the Armenian genocide really don't have anniversaries or centennials, or at least they shouldn't. They do deserve recognition and remembrance as instructive history, but recognition should not do damage to the present. 2015 -- a hundred years after the Armenian massacre -- strikes me as the perfect time to pass the resolution.