company politics: any solutions for my problem?

I have worked in a medium division of a global company for 19 years and hold a senior principal engineer position at the moment. I offended my boss for sending a proposal for fixing some problems within the division to his boss (sent to him and cc his boss) about 1.5 years ago. It was a wrong move. I feel that he is trying to kick me out of the company now. However,I reckon that he was not "brave" enough to fire me because (1) his boss and all managers under him know what I did and what I can do for the company. (2) he knows that most technical guys in the division have a good relationship with me, and a couple of very senior engineers are close friends of mine. His tactic seems to upset me and hope that I can resign. His boss is in Europe and let him run this division with minimum interference here.

He was promoted to the current position internally only 2 years ago. A former senior manager recently told me that my boss felt insecure and was under high pressure.I do not want to leave the company (my wife has an excellent job here).I am doing good work, but he keeps trying to find faults with my work. I have not talked to our local HR about it (I feel that the HR staff is working for his interest). One option I am thinking is to let him know that I will report the case to his boss and the whole senior management team at our headquarter if he pushes too hard and does anything unprofessional. Any suggestions?