There is no doubt about that we need a propper DM and when you read news reports or articles of officials of the forces, it will get evident. But as I recently said in another thread, it is also evident that the PM has changed the hierarchy in the government, to directly talk to bureaucrats or the heads of the industry and the forces, without having the actually responsible ministers of the related ministries in between. That might have advantages in some areas, in defence however it isn't because that's a far too big and important field to give a single person all the power, especially a PM that should have a lot of other things on his agenda too. I don't think he wants a propper DM, to intervene directly with the Chiefs, while Arun Jaitly mainly is the Finance Minister and takes the MoD only as a part time job, since the PM is the key anyway.
There is a huge discrepancy between the hard talk of the PM during the elections, with statements about hard and direct retaliation for any attack or incursion at our borders with Pakistan or China. The actions after being in power however are far different and for those though talks earlier, are actually looking weak. For days we had incursions from the Chinese, for weeks or even months tensions are raising at Pak borders, the embassy attack in Afghanistan..., but no official response from the PM or the part time DM! It don't need to be an insane statement based on emotions, that only makes things worse, but at least a public address to the Government of Pakistan to take actions, or even a open remark during the visit of Xi Jinping that would had put more pressure on him to resolve issues about the incursions would be important.