Written by Jim Roberts

Vietnam War era Cluster Bomb

The story below is adapted from Jim Roberts’s book, MAT 111 Dong Xoai, Vietnam 1971: Stories from 33 Quebec’s Tour of Duty. Cluster munitions and cluster bombs are in the news today because of the controversial decision by the United States to supply the ordnance to Ukraine for its war against Russia. Jim’s story reminds us that cluster bombs were sensitive and unusually dangerous from the beginning.

In 1971, I was an Infantry Lieutenant in Vietnam with Mobile Advisory Team (MAT ) 111 based in the village of Dong Xoai advising South Vietnamese Regional and Forces.

Jim Roberts in Vietnam and Vietnam war map in 1971

It was there I had my first encounter with CBUs—Cluster Bomb Units or cluster munitions, the kind so much in the news today because of their sale by the United States to Ukraine for its war against Russia.

I ran across the CBUs during one of our walks in the woods.” These were short patrols to some designated remote location, usually out of radio or artillery range, with no specific objective apart from checking out” the area and reporting back anything notable.

Our dismount point was twelve clicks from the camp. I accompanied about twenty South Vietnamese soldiers on the operation. We’d patrol west, then turn south before following a line of march back to the road. Total time: three days.

After two uneventful days, we began our final march along a valley canopied with small trees. We had been moving about thirty minutes when the point element stopped and signaled for my South Vietnamese counterpart, Company Commander Captain Ky, to come forward.

I moved up quietly behind Ky, trailed by my interpreter.

The two soldiers on point were kneeling down looking at a gray metal sphere about the size of a tennis ball. Nearby was another strange-looking device with what looked like wings.

My eyes widened, and I told my interpreter to tell Captain Ky to pull everyone back.

I’d been briefed on this object at Fort Bragg’s Center for Special Warfare. I recall the doors to the meeting room being flanked with armed guards with a sign: SECRET BRIEFING IN PROGRESS.”

The briefing was cursory, but the field experience that afternoon led by a Green Beret NCO was eye-opening. He went into great detail on how these gray tennis balls worked and disassembled one as part of his demonstration.

Never operate in an area where these have been used, if you can help it,” he said. Too risky.”

This new secret munition was a CBU — Cluster Bomb Unit.

When dropped by aircraft, the CBU opens at a predetermined altitude and spreads upwards of 200 tennis-ball sized bomblets” over a wide area. The 155 mm Howitzer fires a similar device that could deploy 40 bomblets. The winged unit aids the dispersal and orients the explosive sphere during the fall so it explodes on contact with the ground.

They’re essentially air-dropped grenades but with no delay before exploding.

The main problem with this ordnance is that not all of them explode. They can lie dormant for days, months, years, and then go off when touched. They can also get caught in thick jungle foliage, then drop with devastating result when a passer-by jostles a vine or branch.

The discovery of a CBU on our route, in our District, was a troubling surprise. I moved back to take a closer look at it.

The fusing device on the ball appeared to have triggered. If I was correct, that meant it was a dud and would never explode.

1971 Vietnam CBU (Cluster Bomb Unit) bomblet

A 1971 Cluster Bomb winged deliver unit

The CBU bomblet and the cluster bomb winged delivery unit Jim found in Vietnam in 1971 (Jim Roberts).

I explained the situation quickly to Captain Ky. He ordered his troops to freeze in place and look around for any other CBUs that might be lying about. One was reported near the front of the column.

Our field radio with its 10-foot-long collapsible antenna was just close enough to base to make contact. I used it to request a change in our line of march away from the CBU field. We waited for the message to be relayed from Radio Watch to Province HQ.

Radio Watch finally crackled back to life: Negative on your request.”

I told Radio Watch to write down my exact words and pass them to Province:

Encountered cluster munitions. Unexploded Charlie-Bravo-Uniforms encountered on ground. Cannot move forward. Must reroute.”

Roger Wilco,” responded Radio Watch.

A longer wait.

Radio Watch came back with a word-for-word reply:

Specified ordnance never used this Alpha Oscar (AO – Area of Operation). Advise counterpart to proceed on original line of march.”

Captain Ky looked at me and said through the interpreter that he would not follow that advice.

Captain,” I said, I agree. My advice is to reverse course and move on a different line of march to the road.”

He smiled, nodded his head, and spoke to his XO telling him to return to the rear and move the column back to the overnight position.

From the US Army’s perspective, I had just committed two serious transgressions.

First, I had mentioned classified information on an open radio channel.

Second, I was disobeying a direct order.

I thought for a moment and began seething silently with anger.

Some desk jockey in an air-conditioned office at Song Be had carelessly tossed off an order based on incorrect information. As a result, someone might get killed, maybe me.

I returned to the gray metal sphere and winged delivery unit, picked them up, and put them in my pack. Carrying unexploded ordnance is a court martial offense. That made three transgressions.

We returned from the patrol and entered our team house at Dong Xoai.

What on earth did you do, LT?” asked Radio Watch as I walked in. The Colonel at Song Be wants to see you immediately. He’s not happy.”

Next morning I boarded the work chopper and flew the 25 miles to headquarters.

The Colonel’s jeep was waiting for me at the airstrip.

What did you do, LT?” asked the driver. The S-2 (Intelligence) and the S-3 (Operations) officers are in the Old Man’s office waiting for you. It looks like you stepped into some deep shit.”

I knocked on the office door frame.

Come in,” the Colonel barked.

I strode in at full height and stood at attention in front of the Colonel’s desk.

Lieutenant Roberts reporting as ordered, Sir.”

Lieutenant, you sent classified information over an open radio frequency, is that correct?”

Sir, yes sir,” I responded.

Your counterpart did not follow the prescribed line of march for the operation and changed the pick-up point. Is that correct?”

Sir, yes sir.”

Do you have any idea why he did not follow your advice?”

Sir,” I said, he followed the advice I gave him.”

Do you have anything else to say before being dismissed?”

Sir,” I explained, we were to gather intel on the operation, and we encountered something none of us had ever seen in the district. Being told that cluster munitions were never deployed in the AO, and not knowing what we had encountered, I thought it would be best if I brought the item back so the S- 2 could have it analyzed in case the NVA are deploying something new and unknown to us.”

I pulled the winged delivery unit out of my bag and placed it on the Colonel’s desk.

The Colonel straightened in his chair, as did the S-2 and S-3 officers, sitting silently to the side.

And there is this.” I placed the gray metal tennis ball sized sphere on the Colonel’s desk next to the winged unit.”

It’s inert, Sir. I removed the firing mechanism and the explosive charge. I was thoroughly briefed on this munition at Fort Bragg.”

The Colonel’s face blanched as he stared at the two devices.

That will be all Lieutenant,” he said, without looking up.

I did an about face and marched out of his office, trying my best not to glance at the S-2 and S-3 as I exited.

I never heard another word about the cluster bomb incident, and I was still a First when I DEROSed (Date Eligible for Return from Over Seas) several months later.

Top image: Demonstration cluster bomb, US Army, Rocky Mountain Arsenal. U.S. Honest John missile warhead cutaway around 1960, showing M134 bomblets filled with Sarin (wikimedia)