I don't even like Mi6 and I'd probably fight for them rather than against them in this situation. Sengooku is acting like a little kid who is shouting, "Neener neener, you can't hit me," whilst cowering like gutless cowards behind their big brother's skirts.
In that sense, Sargun's PR game is working, there are people starting to say, "YEah, it is Mi6, uggh, but damn... Sengooku is full of punk little b#tches."
It is my guess folks are bored and Mi6 is an easy target.
If it was me, I'd order mi6 into peace mode, post a recognition of war, wait until Senguooku was balls deep in another larger war, and then blitz them. Either way Mi6 is going to take a beating, but you might as well return the favor to Sengookue by forcing them into a crappy situation like they are trying to do to Mi6 now.