President Obama more than likely will have to put more U.S. troops on the ground if his effort to provide humanitarian aid to the Yazidis trapped on Mount Sinjar in northern Iraq is truly to succeed.

I say that having watched a similar U.S.-led effort to airdrop food, tents and medical supplies to Iraqi Kurds driven into the same northern mountains by Saddam Hussein's military in the wake of Desert Storm in 1991.

On that occasion, President George H.W. Bush decided not to pursue the Iraqi military into their homeland after pushing them out of Kuwait. Instead, he urged the Kurds to rise up against Saddam on their own. They tried, failed, and by the thousands were forced from their homes and brutally expelled to the mountains, trapped between Iraqi soldiers and Turkish forces that refused to let them cross the border to safety.

Photographer Stormi Greener and I were there, reporting for this newspaper.

Initial airdrops failed, even when they hit their target zones. Immediately a battle for survival of the fittest erupted. The fastest and the strongest won — those who reached the aid pallets first and could carry the most. Trucks carrying bottled water up the mountains were ripped of their cargo before coming close to the top. A black market arose overnight, those who had selling to those who had nothing. Fairness was absent.

The United Nations, which was in charge, called for help. The United States led the response, sending a squadron of helicopters and a unit of Green Berets. Along with roll after roll of barbed wire. Order was restored. Black-marketeering almost disappeared. Fairness prevailed.

Airdrops stopped. Helicopters ferried the aid to designated zones, protected by coiled wire. Two or three heavily armed Berets guarded each zone.

Beret commanders summoned the leader of each Iraqi extended family, tribal group, religious group or political faction. Each received a specific time and place to periodically pick up sufficient aid for their group — and for no other.

It worked, until negotiated agreements allowed the Kurds to return home.

Stormi and I had been living hand to mouth. Sleeping chilled nights in our cramped, tiny rented car. Eating cold pork meals ready to eat (MREs) from the airdrops discarded by the Muslim Kurds, to whom pork is a no-no. There were no hotels, no restaurants.

When the Green Berets landed, we sought them out, thinking we might be able to park our car next to their bivouac for overnight security. When I walked in, the first soldier I met was the executive officer. I told him our situation, and he immediately invited us to join them. "We have plenty of room." So, in effect, we became embedded journalists.

I asked the Berets why they were chosen for this duty, far from their base in Germany. "Well," one replied, "our first priority is we are killers. Humanitarian assistance is also on our list, too. About number six or seven."

Clearly, those chopper pilots, crews and Berets knew what they were doing.

But there is every reason to expect the same survival of the fittest battles to break out among the Yazidis, estimated to number between 40,000 and 100,000, as the airdrops continue to hit the ground around them. Why not? They are under great stress and face great needs. Why should they react any differently than most people chasing airdrops anywhere around the world in similar circumstances, as experience has shown? And as the trapped Kurds did in 1991 before U.S. boots arrived on the ground?

The next question is whether President Obama will be willing to expand U.S. military presence in Iraq even more by putting those boots on Mount Sinjar.

Frank Wright is a retired Star Tribune journalist.