Confirming grammar about verb potential form

Question

異三郎の動かせる勢力の全てを島に投下

動かせる is a verb in potential form

I heard that when の particle meets a verb it usually means its a relative clause but I'm quite sure this is not the case for this sentence

So is it correct if I consider 動かせる is more of an adjective than a verb (so it means more like force that can be moved)

So that the whole sentence would roughly translate into: All of Isaburo's forces that can be moved is invest on the island

Answer 1

Japanese potential forms are a bit tricky, but the following three sentences are all correct:

• 異三郎は勢力を動かせる。
  Izaburo can move the force.
• 勢力は(異三郎によって)動かせる。
  The force is movable (by Izaburo).
• 異三郎には勢力が動かせる。
  To Izaburo, the force is movable.

These are chosen depending on the topic of the sentence. English speakers may find the first 動かせる is verb-like ("can move") and the other two are adjective-like ("movable"). See also: The difference between が and を with the potential form of a verb and Use of に in 「私には本物の若殿様がわかります」

Anyway, the sentence in question can be constructed straightforwardly from the first bullet above.

• 異三郎は勢力を動かせる。
  Izaburo can move the force.
• 異三郎が動かせる勢力 (pull out 勢力 and change wa to ga)
  the force Izaburo can move
• 異三郎の動かせる勢力 (ga-no conversion)
  the force Izaburo can move

So 異三郎の動かせる is a relative clause, and this の is a subject marker that can be used inside relative clauses. If you are familiar with ga-no conversion, this grammar should be simplest to English speakers. Compare the following:

• 異三郎の動かす勢力
  the force Izaburo moves
• 異三郎の動かせる勢力
  the force Izaburo can move

Answer 2

In this case の can be replaced with が. so 「異三郎の動かせる」 is same as 「異三郎が動かせる」. This question is often asked in Japanese language tests in Japan :-).

Answer 3

Either way, it is a relative clause. The question is whether the part marked with の is inside of it or not. In this particular context, I would say it is in.

［異三郎の動かせる］勢力

異三郎 is the one who can do the moving, or the subject of 動かす. The noun phrase can be rephrased to:

［異三郎が動かせる］勢力

Although one might argue such things as fixed artillery are 動かせない戦力 and other types of weaponry as well as troops and vehicles are 動かせる戦力, this distinction doesn’t seem a very common concept. At least, it is not important here. The focus in this context is rather on whether 異三郎 can, or is authorized to, deploy those forces. It would make more sense if the subject were specified.

The same verb may be used to refer to a more intrinsic attribute of something, though.

この会社の［動かせる資産］

Here, whether the company actually moves these assets may not be so important as the fact that they are intrinsically “movable”.

燃やせるごみ and 裂けるチーズ are other examples. Though 裂ける is considered a separate intransitive verb, it is essentially the same as the potential form of 裂く.