But...but...Indonesia is pretty large!
The Roman Empire can similarly be analyzed as "acquired" through time, rather than "set out to get one". At least, up until say Caesar or perhaps a bit earlier. At least in the first couple of centuries the Romans just seem to attack those who annoy them, then leave, then attack again because they're provoked, and leave again, then have to attack YET AGAIN, and then they decide to stick around to prevent further wars.