NATO type alliance is not ummah concept. Ummah concept is the Khilafah whereby at the very least a very large Islamic power leads the Islamic world with many smaller Muslim powers in alliance with the Khilafah. At the very best all Muslim lands in the world are brought under one rule, ruled by a Khalifah. The former is achievable while the later is nearly impossible. The former concept is not a bad concept IMO, if you look closely at the western powers, they are exactly that; led by USA with many smaller western powers in a NATO alliance. It's working greatly for them so far.I was not talking about all Qawumis though.
However for the rest of your post no disagreement. But NATO type alliance is ummah concept .
I asked your opinion for the ruling system of Bangladesh ,since we have no other option than controlled democracy at this moment.
The ruling system of Bangladesh should be pure democracy. Democracy is not something easy to achieve, it will take many struggles, many sacrifices, many mistakes before we get there. Europeans got there the same way. As much as we wish to resolve our issues as soon as possible, there is unfortunately no shortcut. We have taken some baby steps towards democracy since the fall of Ershad, we fell, we rose and it will continue like that. Next big step to take is to eliminate dynasties and ensure it never ever takes root again.