Thursday, January 12, 2023

A Proper Understanding of the 3:1 Rule

This author explains how he wargamed a 1994 Iraqi invasion of Kuwait. I loved it.

Exactly!

While the conventional wisdom that the attacker requires a 3:1 superiority to succeed, the Soviet/Russian Correlation of Forces Methodology is more sophisticated and recognizes that as long as a commander can do economy of force operations in some sectors to enable concentration in others sufficient to overcome the defender, even an overall inferiority of combat power can be made to work. In this case, a 1:1 will serve the purpose.

The Russians have a reputation of using massive force on the World War II Eastern Front. They did. But as they gained strategic initiative they stripped the front away from the main offensive to get that local massive superiority. The Germans didn't know that the Russians thinned out their lines and couldn't have exploited that if they knew. So it looked like Russia just had overwhelming numbers everywhere.

My long history of playing commercial board wargames made that obvious to me with back-of-the-envelope calculations, when I looked at an initial Iranian invasion of Iraq after America left. I assumed Iran would try to storm the capital with another drive into the Shia south, and try to win it all:

I estimate that Iraq's ground forces have a combat potential of 44 points. Iran has 140 points. This is more than a 3:1 advantage overall. That's a decisive margin.

Iraq could deploy a higher portion of their forces on their eastern border in the center (forward of Baghdad) and south (forward of Basra). I'll call it as 34 points there with 10 points in the far north and west. Iran would have 9 points in their northwest Kurdish region, 25 close to Tehran, 9 on the Afghan border, 9 on the Pakistan border, and 9 on their coast. That leaves 79 points for the main fronts in the center and south.

So Iran would have 79 ground points to Iraq's 34. With more than 2:1 at this scale, that is decisive. I know that a lot of writers would look at those numbers and chant the "3:1 rule" and say Iraq is safe, but that ratio applies to lower levels of analysis (and then considers the benefits of terrain and other factors on the "points" of the basic units). One side in a campaign with even a 1:1 equality overall could strip forces along the front to reduce local balances to 2:3 while massing combat power at the point of attack up to 6:1 or higher.  

I concluded Iran had the short-term advantage, although I wondered if Iran could sustain the offensive.

Then I looked at likely American reinforcements if America kept troops in Iraq. Which I wanted to do:

American forces would play an important role in this short run. If we keep 3 Army brigades in Iraq, as I want, we'd add 27 points (I assume 9 per Army brigade). Toss in an afloat Marine Expedionary Unit (4 points) that could be landed quickly, and maybe another Army brigade in Kuwait, and we'd add 40 points to Iraq's total. Add in the equipment of two more Army brigades in the region that could be quickly manned by troops flown in and a Marine Expeditionary Brigade with equipment afloat (15 points), and we'd be able to quickly add 33 more points, for a total of 73 American ground points. Now the Iranians face a deficit of 79 to 107 US/Iraqi points. Add in the effects of American air power, which could double the effectiveness of American ground power, and the war would quickly become a matter of Iran defending Khuzestan (or Arabistan as the Iraqis probably still like to call it).

Granted, these numbers are just educated guesses on my part, but that's what the process would look like with real numbers based on deeper knowledge of the forces involved. Even with my limitations, clearly, with even a small American force inside Iraq with more on call, Iran wouldn't even try to invade and could not pressure Iraqi officials with that threat.

That initial author had deeper knowledge and real numbers. Do read it all.

I have a long history of battling that conventional wisdom. And we really need to do better.

So yeah, I really enjoyed that author's work. 

NOTE: Winter War of 2022 coverage continues here.