First, iaido: it is a noncombat activity, according to Diane Skoss, a noted kenjutsu authority. By that she means it was a dojo method not intended for real combat. So don't expect to find European analogs in any of the manuals. Iaido is play, not combat
It's an oversimplification. I doubt she formulated it like that, quote?
Sorry, it's not Diane, per se, but from an article by Hunter Armstrong entitled "The Koryu Bujutsu Experience," in
Koryu Bujutsu: Classical Warrior Traditions of Japan, D. Skoss ed. (Berkeley Heights, NJ: Koryu Books, 1995), pp. 19-38.
Although the discussion about the noncombat nature of iaido is quite long, here is a useful passage to give you the flavor:
Batto (and other solo weapons practice) was primarily used for selfpractice when one didn't have a partner. In most classical dojo, very little time was devoted to solo practice. In some modern dojo, the emphasis may have changed, but in most classical traditions in Japan, such practice is still a relatively minor part of the overall training regimen of the ryu. For example, in Shinkage-ryu (founded by Kamiizumi Ise-no-Kami) and Yagyu Shinkage-ryu (founded by Kamiizumi's student Yagyu Munetoshi), there is either no batto, or it is done as a minor part of the overall kenjutsu training. (In the Yagyukai of Yagyu Nobuharu Sensei, there is no Yagyu-ryu sword-drawing per se; however, Nobuharu's grandfather developed Yagyu Seigo-ryu batto explicitly for modern purposes.) In Shinkage-ryu, the batto is essentially a preparation for two-man, sword-drawing kenjutsu with shinken (closer still to combative reality).
The distinguishing key, again, is realistic preparation for combat.
Iaido, whether derived from a koryu or not,15 has no such aspiration.
Its aim is the development of aesthetic sword movement and spiritual, moral training, and the emphasis varies according to the interpretation of the individual performing the art. These are fine aims, perhaps even better than seeking combative effectiveness. Why confuse the two very different ends? Yet, there are practitioners of iaido who consistently contend that their art is combatively effective and cite apocryphal rationales as proof. One that is commonly heard is that iaido was developed on the battlefield for when a warrior's spear or other weapon was broken or became useless for some reason, and he had to quickly draw his sword to defend himself and continue fighting. First of all, extremely few of the koryu practice any kind of sword-draw while wearing armor, much less quick-draw techniques. On the other hand, several of the extant koryu do practice various weapon-systems in armor, including kenjutsu, sojutsu, kogusoku, etc.
If being able to perform a quick draw while wearing katchu (armor) was so important, one would think that the skill would have been maintained and be more evident. Secondly, and most importantly, drawing a sword while in armor is quite a different matter from drawing while wearing everyday clothes.
The bushi in armor would only draw his tachil7 if he had the time and distance to effectively do so; if a fast draw was necessary, it was probably already too late for the longer blade, and he would resort to shorter weapons and grappling. When an enemy was so close or moving in so rapidly that a warrior's weapon became useless, the bushi was trained to resort to armored grappling (kumiuchi or kogusoku) with a short-bladed weapon such as a wakizashi, yoroidoshi, or hachiwari.18
This was more effective than trying to draw his tachi or katana. Takenouchi-ryu and Yagyu Shingan-ryu are two well-known traditions that put a great deal of emphasis on two-man training in these types of closein combat with shorter blades. Shinkage-ryu also practices kogusoku with kodachi (short sword). In any case, even if the armored quick-draw was feasible on the battlefield, the speed of the draw is not nearly as important as awareness, distancing, timing, and targeting, none of which are aspects of solo, sword-drawing practice.
Another rationale for the iaido quick draw is its development as "samurai self-defense." Supposedly, when the warrior was attacked while walking around minding his own business, iaido training prepared him to quickly draw his sword and defend himself. This is really not much different from the rationale for the quick-draw on the battlefield. Realistically, old world or modern, if an attack occurs so quickly as to require a fast draw from an evidently non-alert defender, the defender loses. The most important principle in heiho for not being defeated by surprise is to avoid being stoprised. The chances of surviving a sudden attack are very small. The best way to avoid being "suckerpunched" is not to be in a position that allows one to be suckerpunched. What is necessary for realistic combative situations— particularly in potential surprise attacks—is mental and physical preparedness.19 The average bushi relied on skills gained in training with opponents, not on training by himself.
In reality, iaido, as a solo implement training discipline, has more in common with kyudo than with kenjutsu; both iaido and kyudo do not include the dynamism supplied by facing an opponent who possesses intent.
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