The thing is, those two units are not in fact comparable in combat power; and it surprises me that Weber would make an invalid comparison like that, because although he himself didn't serve (at least according to any bio source I can find), he majored in Military History in college, and he generally gets that sort of thing down pat.
Anyway, I can see an ACS (armored combat suit) being as tough and having the firepower of an MBT; in fact that's exactly what I was thinking of in terms of combat power BEFORE I heard Webers comparison. An infantry company however, if properly armed and employed, is significantly more combat power than a single tank. In fact, an infantry company, SHOULD be equivalent in combat power to an Armor company, assuming either in their most effective circumstances.
In actuality, I'd say an armored company COULD be more effective than an infantry company even in suboptimal terrain because a tank troop is a fair bit of combat power; but up the command size just a bit, and give me a batallion of mechanized infantry, with a heavy weapons company, a heavy weapons platoon in each of the companies, and light armored transport (most modern ifnantry, whether they call themselves mechanized or not, are at least partially so. Only infantry explicitly defined as "light infantry" are generally not), plus fast softies; and given broken and obstructed terrain with heavy cover, that batallion will in fact be far MORE combat effective than an armored batallion.
Of course put that same infantry batallion in the desert, and the tanks will chew them to pieces.
It's a matter of mission suitability. There are three basic types of ground combatant: Infantry, Cavalry (now armor), and Artillery. In each of their respective operational environments, a batallion of infantry should be as effective as a batallion of armor, should be as effective as a batallion of artillery etc...
Why mission suitability?
Well, in open terrain with a little bit of cover, good traction, and no rivers or big hills (say, the hard desert or tundra), a company of tanks is about the most effective combat unit possible (at least with tanks today). In that same terrain, an infantry company would be effectively slaughtered by artillery or armor (assuming they are mounting adequate anti-personel weapons).
If there is just enough terrain and cover to slow the tanks down though, the artillery battery is going to completely destroy the tanks, whereas the infantry will have enough cover to at least survive if not be effective, and if they have the right weapons mix they're going to at worst trade even with the tanks.
Roughen the terrain up more; include steep slopes, hard structures, lots of cover etc... and artillery is only marginally effective (well... until it pounds the cover to dust anyway), though it may keep infantry or armor from being too effective; and armor is in it's worst possible environment, because what keeps armor alive is, oxymoronically not the armor on the vehicles, but the mobility that armor presents (thus the armored cavalry tradition). Infantry on the other hand is in it's ideal environment, and it can use the cover and terrain effectively to neutralize both the armor and artillery (again assuming proper weapons mix).
Artillery has often been called the king, (or queen depending on your military tradition) of the battlefield. Artillery is the nightmare of both armor in the rough, and infantry in the open; and has perhaps the most broad range of effectiveness. You can never have too much arty (assuming well regulated), and there are very few situations in which you can't use at least a little bit. The problem of course is that artillery is only minimally mobile in comparison to armor or infantry. This means that it has to be pre-laid in appropriate positions in order to be most effective. Some artillery types CAN operate on the fly, but effectiveness is highly variable there. This allows armor and infantry to use mobility to eventually get inside the effective range for final protective fire on an artillery position, and destroy it... if there are any left that is.
Obviously this parity isn't always the case, as variances in missions, equipment, leadership, training, and forces structure make HUGE differences; but in gross, you can generally assume equivalence from line combat division to line combat division; given suitable missions for each type of ground combatant (and assuming the same approximate definition for division).
Let's see I've talked about companies, battalions, divisions... what exactly do those mean?
Each is a particular sized unit, with a particular rank for it's commander. Unfortunately these sizes and ranks aren't exactly entirely consistent across nations, across different armed force types, or even across types and specialties of division within the same army; and they can be rather confusing.
Lets break the various command elements down for the reader in the next section shall we?
The point of all this, is to help out readers, who may not have a familiarity with military command structure; in deciphering what an author means when he says that a regiment is going to get hit by 4-6 divisions, and get destroyed in the process...
That is effectively what Leonidas and Demophilias did at Thermopylae, before being slaughtered when the massed armies found a way around them and killed them from the rear. 300 spartan soldiers, 700 citizens pressed into arms, and 400 unwilling allies defended the pass at thermopylae against somewhere between 40,000 and 120,000 men directly assaulting them; and perhaps as many as 800,000 men behind them (historians widely disagree as to the numbers present).
The example is popular among military writers, not only for it's valor, but also for its stupidity; and for the fact that Thucydides, Simonidies, and Herodetus wrote "histories" of the account, with a masterful use of language. There is a monument on the site which reads
- Go tell the Spartans, stranger passing by,
- that here, obedient to their laws, we lie
Anyway, on to the important info here.
The basic combat element in almost any military is infantry; and forces structures are generally defined based on their equivalent infantry structure, so rather than make this thing 30 pages long, we're going to base it on infantry. I'll also include some notes on other service command equivalences, but often naval commands don't map exactly to army commands. Air Force commands don't even make sense to me, and I SERVED in the AF; never mind mapping to the command structure of the other armed services (Colonels may command as few as a few dozen people for example, or may command a full regiment sized unit).
Also I'm going to try and cover most of western military tradition here, not just the U.S.; and I'm going to try and be as general as possible. Once you get deep into the specifics of individual nations armies (and especially navies and air forces) the intracacies can be mind boggling (as the Heartless Libertarian points out below).
Now, the first four infantry command elements (pair, team, squad, platoon) are generally informal or semi-formal organizations within a company. They may or may not exist within a given command, and may be without a recognized or acknowledged command hierarchy, except within the company. Importantly, the command structure of these smaller formations is fluid, and is generally decided on, and changed by, the company commander, in consultation with his platoon leaders, staff, and cadre; and without formal promotion or assumption of command.
Regarding command structure in general, one should note the technical distinction between a leader and commander. A leader makes tactical decisions and gives direction (and possibly commands which are distinct from orders) but not necessarily orders. A commander is legally as well as tactically and strategically responsible for the actions carried out under him, and gives orders (as well as direction, decisions, and commands). Formally and legalistically speaking, anyone can be a leader, even a private; but only a commissioned officer is a commander.
Pair, Partner, or Combat Buddies: Two soldiers paired together for mutual support.
(Fire)Team(or Section): Usually four to six soldiers (sometimes eight), may or may not have a designated leader, usually a corporal or sergeant.
Squad(or Section): From 5 to 14 individual soldiers, generally lead by a corporal or a sergeant, but may be lead by a staff sergeant. May or may not be subdivided into two or three fire-teams. MAY be commanded by a second lieutenant in some specialties.
This may also be equivalent to a naval section, depending on specialty, and would generally be lead by a petty officer third or second class.
Platoon (sometimes also called a Section): Two to Four squads (or sections) comprised of anywhere from 20-40 men, and generally commanded by a lieutenant, assisted by a platoon sergeant. There are some special platoons or sections that may be commanded by a captain (generally a highly technical or special operations specialty).
A platoon is generally the smallest command element commanded by a commissioned officer. In the cases where a section is lead by a lieutenant, that officer is generally acting as a leader but not as a commander.
The platoon/section can also be equivalent to a naval section, though a section is more likely lead by an NCO (a chief or PO/1c).
Company( sometimes called a Troop - in armored cavalry - or a Squadron): A formal command element generally consisting of 3 to 5 platoons (may have as little as two or as many as six platoons), and anywhere from 80 to 250 or even 300 soldiers depending on specialties (typically 120-160). A company is generally commanded by a Captain, but in some armies, and in some specialties a company may be commanded by a Major, especially if it is a larger company. The company commander is assisted by the command staff (typically intelligence, logistics, and communications officers or sergeants);the cadre, lead by the first sergeant (who may or may not be a Sergeant first class); and by their platoon leaders.
The company is the basic infantry combat unit in almost all armies. The company commander is often considered to be the best pure combat command level, as there are fewer strategic, political, and logistic issues to consider outside of basic mission parameters.
The equivalent Naval command would be a small boat command (which would consist of one medium or large boat but not a ship, or several smaller boats in a squadron), or a shore section command, which would be commanded by a Naval Lieutenant (the equivalent to an Army Captain
battalion(also sometimes called a Squadron): A batallion generally consists of four or five companies, but may have as few as two, or as many as six, and from three hundred to one thousand soldiers, depending on the specialty. Some armies may not use battalions, simply organizing companies into regiments. Smaller battalions may be commanded by a major, but larger battalions in most specialties will be commanded by a Lt. Colonel, assisted by a full command staff (usually a light company), including intelligence, plans and operations, communications, logistics and supply officers, and generally having a Master Sergeant or Sergeant Major as the leader of the Cadre.
The naval command equivalent would be a small ship, or a large boat squadron, commanded by a Lt. Commander, up to a medium ship or submarine (also called a boat) commanded by a Commander.
Regiment: A regiments has from two to five battalions, or may have only companies without a batallion structure, or squadrons without batallion structure (in the case of cavalry divisions) and generally consists of 1000 to 2500 men, though it may have up to 3500 (for a pocket brigade). Some armies may not use regiments, simply organizing battalions into brigades. A regiment is almost always commanded by a full Colonel; however there are some organizations called regiments, which are effectively small brigades (called pocket brigades), and which are generally commanded by brigadier Generals. A regiment will have at least a headquarters company, and may have an HQ batallion with a full staff section, and Cadre lead by a Sergeant Major.
The Naval command equivalent would be a medium to large ship command, or a small group of small or medium ships (which may or may not be called a squadron), commanded by a naval captain.
Brigade: A brigade consists of two to five regiments, and generally from 1500 to 3500 soldiers., but may have as few as 1000 and as many as 5000. Some armies may not use brigades, simply organizing regiments or battalions into Divisions. A brigade is generally commanded by a brigadier general, but may be commanded by a major general for a heavy brigade, or a special or very prestigious command. A brigade will have a Sergeant Major as it's Cadre leader (generally a command sergeant major, or chief sergeant major - which may or may not be a formal rank).
The naval command equivalent would be a very large ship command, or a squadron or group command of medium to large ships, commanded by a Rear Admiral (lower half), or a Commodore.
Division: A division will have two to five brigades, or may be broken into five to ten regiments without a brigade structure, and typically consists of from 10,000 to 20,000 men, but may have as few as 5,000, and as many as 30,000 for some specialties. A division will generally be commanded by a Major General, but for some smaller divisions may be commanded by a brigadier General, and for larger divisions or very prestigious commands may be commanded by a Lieutenant General.
The naval command equivalent would be a battle group, task force, or heavy squadron, commanded by a Rear Admiral, or a vice admiral
Corps: A Corps generally consists of two to three divisions, and generally 30-50,000 men; though there may be as many as five divisions and 100,000 men for a heavy corps. A corps is generally commanded by a Lieutenant General, but may be commanded by a General for a Heavy Corps.
The naval command equivalent could be a small fleet, or large battle group, commanded by a vice admiral.
Army: An army generally consists of two or three corps, and anywhere from 50,000 to 100,000 men and is commanded by a full General (four star), or a Marshall; though in World War Two some were commanded by Lieutenant Generals.
The naval command equivalent would be a navy, a large fleet, or a fleet group; commanded by a full admiral.
Army Group(also Group Army, or Theater Army): An Army Group is two to five Armies, anywhere from 100,000 to 500,000 men, and is commanded by a general of the army (five star) or Field Marshall; and is generally the largest unified command structure employed by organized militaries in war.
The naval equivalent command would be a naval group (multiple fleets), or naval theater, commanded by a fleet admiral.
UPDATE: Reader "Heartless Libertarian" adds the following detail
"Note: the equivalent of an infantry company in the cavalry (and, in some countries, armor) is called a Troop, not a squadron.
In the artillery, it's called a battery (also in air defense artillery).
In the US Army, things at the regiment & brigade level have gotten a bit wierd. During the Civil War, and possibly as late as the Spanish-American War, regiments were grouped into brigades (commanded, appropriately by a brigadier general).
During the First and Second World Wars, and possibly Korea, brigades disappeared, and regiments were direct components of divisions.
Now, a regiment are pretty much equivalent. Both consist of a 5 to 8 battalions (armored Cav being the biggest, and including organic helicopter battalions), some separate companies, and being commanded by a full colonel.
With the ongoing restructuring, it's even gotten a bit more complicated, as the new 'Brigade Combat Teams' are combined arms entities, with the same commander owning the maneuver battalions (infantry, armor, and/or cavalry), plus the artillery, engineer, and support units. (Previously, Artillery, Engineer, and Logistic units had their own colonel in charge of them who reported to the Division Commander)
In the 82d and 101st divisions, the regiments ARE brigades (and the bases for BCTs), a bit of history preserved thanks to the fact the the 'Airborne (Infantry) Mafia' has historically turned out a very high number of the Army's highest ranking generals.
The other surviving organic regiments are the 2nd Cavalry (now a Stryker BCT), and 3rd Armored Cav, and the 11th (Blackhorse) Armored Cav (the OPFOR at NTC)."
An aside about American military command history:
The entire American military has at times been commanded by effectively a single brigadier General. Even after the great expansion of the military after 1812, there were still very few generals of any type, and the highest rank was effectively Lieutenant General (Winfield Scott to U.S. Grant). In general our militaries have been resistant to rank inflation, with more responsibility given to lower grade officers than in other forces; especially in the U.S. Marine Corps (though the Air Force is something of an exception to this rule).
While many countries have (or have had) marshals, Field marshals, and even Grand marshals, there have only been five Generals of the Army in the history of the United States:
George C. Marshall
Douglas MacArthur
Dwight D. Eisenhower
Henry H. "Hap" Arnold
Omar Bradley
and their equivalent ranked admirals:
William D. Leahy
Ernest J. King
Chester W. Nimitz
William F. "Bull" Halsey
Additionally, there has also been one Admiral of the Navy, George Dewey; and two Generals of the Armies: John J. Pershing, who commanded all U.S. forces in World War One, and George Washington (who never held official rank higher than General, but congress retroactively voted him General of the Armies later).
The largest the U.S. military has ever expanded to was during World War Two, when we had 30 active army corps (including Army Air Force), with over two million men under arms; and almost half of that in the Navy (including the Marin Corps). With a total of three million men actively under arms at one time, and up to six million total serving in uniform; we never appointed a six star general or admiral; and only had nine five star flag officers EVER.
In comparison, the UK, with only about 1 million men under arms at peak, had dozens of marshals and Field marshals; and the Soviet Union had even more.
Many people think that Eisenhower was the Supreme Allied Commander, and equivalent to Pershing in rank; but in actuality, he was the Commander Supreme (Headquarters) Allied Expeditionary Forces (Europe) or SHAEF. Eisenhower was de jure equal in rank to MacArthur, who commanded the pacific theaters expeditionary forces, and in both cases the Naval Forces were not subordinate to their commands; though of course there was a great degree of command deference in most cases.
In fact, in order to explicitly ensure that the naval commands would remain independent of the Supreme Allied Commanders for each theater, secretary of the Navy Frank Knox with the connivance of president Roosevelt (who was also secretary of the navy some years before) deliberately promoted the five star admirals THE DAY BEFORE each of the corresponding generals, so as to ensure a date of rank precedence.
Eisenhower however is almost always considered by historians to be SLIGHTLY "more equal" than the other Generals and Admirals.
Oh, and why were there five five star generals but only four five star admirals? Congressman Carl Vinson, who had a HUGE influence over the navy (so much so they named an Aircraft Carrier after him, along with John Stennis), personally disliked the fifth admiral submitted for the rank, Ray Spruance; and blocked his appointment to the rank, although they officially advanced Spruances pay grade to that of five star.
