They never play fair. Why would they run headstrong into IA's prepared positions when they can sneak into Myanmar and hit us from the back.
India has a wee bit of influence over the Kachin people.
They are kicked around by both China and Myanmar.
If a PLA general is ordered to attack NE India through Myanmar, chances are he would probably invite his Indian counterpart for a round of Old Monk and chicken tikka under the pretext of exercises & 'know your enemy' and quietly snub the CPC.
Northern Myanmar is a hellhole. Ask the Japs.
Now with so many tribes and insurgent groups on payrolls of multiple agencies, and the area being our backyard, you can conduct small terror or SF attacks but an entire invasion would require God himself to lead.
The Kachin people are largely Christians.
For China to have any edge through Burma, the entire state of Nagaland will also have to rise in armed rebellion.
I hope you are aware of our military foot print in the North East.
The odd attack on an Army or security forces convoy is one thing, an invasion is another.
The terrain is inhospitable. If they can take advantage of it, that would apply to us too, would it not?