I am not talking about capturing it, merely destroying the road and railway links so reinforcements cannot reach NE in time and then launching the main attack at NE. No supply lines are required to do that. When and if that happens, it will be so sudden you won't have time to react. you are talking about 12-15 hrs. you won't even know about it until the chinese have destroyed the link and went back safely. There is a reason why Siliguri corridor has been on the target of IDR. There won't be any double front squeeze because chinese won't stay. They want AP, not chicken's neck.
PS: attack on Siliguri corridor will come from Thumbi valley, not AP since thumbi provides shortest distance.
You can destroy a road link, no doubt. But how many kilometers do you destroy?? You cant go about obliterating hundreds of kilometers of railway network. Just not feasible.
Now for the road link. How do you destroy a road link? Bombing it, showering it with runway denial minitions perhaps. Then what happens? There is perfectly good enough plain area around the road which can be used to move vehicles. And in any case, till a few years back the roads were so full of potholes one would be forgiven to think the road was bombed to high heaven.
You could target bridges though. But then Bear in mind after Brahmaputra bridge near Goalpara there is no major bridge that can be destroyed as a stopping bloc to Siliguri. And even then there is another way which is rougly the same distance from Guwahati, through Barpeta Chariali. And thats solid road.
There is a reason armies cut off road routes by force presence or use of artillery as area denial weapons and not by air strikes or missile strikes. It just doesnt work. Even during 1971, we simply avoided roads and marched into Dhaka. The lack of roads did not stun us then, did they?
If the Chinese want to cut off NE, they will have to put in men on the ground, or nuke the plce to high heaven.
And when I mentioned about AP, I meant that such an attack would have to break into the plains and engage the armored groups in NE, or else these very groups would be available for combat in Siliguri