MD83 CREW FOLLOWED TCASII RA TO AVOID NMAC WITH FLT OF 2 F15'S.

Narrative

WE WERE LEVELING AT 10000 FT AS PER THE ARR CLRNC; WHEN I NOTICED A TARGET AT 6 MI ON THE OUTER EDGE OF THE TCASII DISPLAY; 300 FT HIGH AND DSNDING. IT LEVELED CO-ALT AND CONTINUED APCHING ON THE SAME AZIMUTH OF ABOUT 1 O'CLOCK POS AT 4 MI. I QUESTIONED APCH CTL ABOUT THE CONTACT AND PICKED UP ANOTHER ONE AT 2 O'CLOCK POS; ALSO APCHING. AT 3 MI; WITH TA (TA ON THE TCASII); I INITIATED A L TURN TO CHANGE THE CLOSURE. AFTER INITIATING THE TURN; WE RECEIVED A CLBING RA ON THE TCASII FOR A 2000 FPM CLB. I CONTINUED THE L TURN AND WENT TO A 2000 FPM CLB. APCH CTL THEN ISSUED THEIR FIRST AVOIDANCE VECTOR TO A HDG 60 DEGS L OF OUR ORIGINAL HDG. WE CONTINUED L TO THAT HDG AND LEVELED OFF AT 11000 FT (1000 FT HIGH). I FOUND OUT LATER THAT APCH CTL ISSUED THE FLT OF 2 F15'S A R TURN OF 70 DEGS AND A DSCNT WHEN THEY WERE 2-4 MI FROM OUR POS. I ESTIMATE A MISS DISTANCE OF ABOUT 1 MI HORIZ (OR LESS) AND 1000 FT VERT FROM MY LAST OBSERVATIONS ON THE TCASII DISPLAY. (WE WERE IMC THE ENTIRE TIME.) I CREDIT TCASII INFO AND GUIDANCE WITH AVOIDING A VERY DISASTROUS SIT.