There are a few misconceptions about tanks, their design and their use which is often misused to support one view or another. One such misuse is the "we used tanks in Vietnam" argument.
A tank is just a vehicle. It can go a lot of places a truck can. Tanks have been used in the mountains, and in the jungle, in deserts and in the arctic. Anyone who has seen the state of the soil in spring or autumn in Ukraine would know that any thank that can go through that, can go anywhere. On the other hand in the summer some soils in the south-east of Ukraine become concrete-like, and can destroy tracks much faster then ‘normal’ soils in (for example) Germany.
The big problem with tanks used on water saturated soils is not how heavy they are (as already pointed out), but how many there are, and how fast they are moving. The tanks used in Vietnam were rarely if ever used in numbers larger then a company, and they rarely moved at speeds faster then 25km/h because more tanks then that moving faster would just tear up an unimproved road surface, which is how tanks get to their tactical area, to make it impossible for use by any other vehicles, including lighter AFVs. That is the reason NATO tanks wear rubber shoes, and Soviet Union build all those reinforced roads heading west. For a developing country to use Western tanks in the same way, they would need to invest in significant road improvement projects in likely areas of operation.
It’s interesting that the Soviet Union supplied Vietnam with T-55s well before the first M-48 arrived in Vietnam, so it seems they had no issues with using tanks in Vietnam. However their lighter tanks are able to move faster over unimproved road surfaces even without rubber feet by using wider tracks since the time of the T-34 design.
By the way to move from rice paddy to rice paddy the tank needs to go over the separating dyke, and that can expose its underbelly, never mind that its hard work for the engine when there is not much of a grip to push the tank over (except in wet season when the things just disintegrate and the tracks fill with the muck).
Besides this, the terrain in SE Asia is varied. It’s not all rice paddies, and it’s not all jungle as some like to stereotype. Neither is Europe all 'tank country', whatever that is.
This is the argument behind design of Soviet tanks. Having a really long range gun is great, but average engagement distances don't warrant anything over 2500m at most, and in SE Asia this would be significantly more reduced. The issue in tank design is not only a balance of speed, armour and gun (penetration over range), but also ACQUISITION and above all the CREW. As I was reminded by a tanker, “if you can’t see ‘em, you can’t hit ‘em”.
There are other differences in design approach to Soviet tanks. One is that small is good so far as acquisition is concerned. Given the ambient terrain undulation anywhere, the Soviet design is less likely to present a viable target to ground units then a larger West European tank. For some comparisons this is as much as a 30% reduction.
The small size of the fighting compartment is not a good argument either. In the East and West tank crews fought in Pz IIIS/IVs, T-34s and Shermans for years, even without air conditioners. Sure it’s nice to have all the comforts, but even air conditioner units break down. Is the crew going to just get out and walk because they can't keep the interior cool? And let’s not forget those tanks had four crewmen in there (not counting the driver).
Reduction of a crewman in the tank is a necessity of modern tanking also. The complexity of the modern tank (beginning in the 60s) is significantly greater then it was in the WW2-1950s generation of tanks, and requires more service personnel. While people argue that the extra crewman is not a hindrance/is a benefit, the M1 (or any West European tank for that instance) requires two service personnel (in addition to the crew) to keep the single vehicle operational (on average). This means that the actual number of M1 crew is 6 not 4. The Soviet designers faced same personnel problems from the T-64 design onwards and most developing countries do also, particularly the larger forces like China and India. In a fleet of 4000 vehicles, this reduces training by six battalions! Now consider Soviet fleet of 27,000. To maintain tank fleets one need to employ not just the tank crews, but support staff also. For Australia's 236 crew of the 59 M1s, the Army also needs 118 electronics and 118 mechanical trades as a minimum.
Singapore also has this problem because it has an economy running at high efficiency (so there is very little spare labour force for recruiting, as is in Australia), and I suspect that the purchase of 30 'spare' Leo2s is not because they like to have 30 spare tanks sitting around, but because they know that realistically they have no hope in hell of finding crews and support staff to maintain them operationally. Australians are just more realistic IMHO. There is another thread on this, but I would suggest that recruiting 2,600 extra service personnel will not produce 500 tankers (and I include armour service personnel in the term because without them the units just don’t function).
This is the real reason Soviet tank designs have been popular with developing countries where personnel with appropriate education are hard to find. Besides that, they are just cheaper to produce even in cost of metal alone by retaining lesser surface and volume thanks to innovative engineering. That is also part of tanking.
Cheers
