Brief but belated research on the fate of the M-60 Tanks roughly runs as follows:
-1700 of the Type are presently operated by the Egyptian Army
-700 of the Type are operated by the tukish army
-Approximately the same number (700) were in the hands of the IDF. In their survice the M-60's were superceded by the home grown "Merkava" (Chariot) Tank. Then 105mm sized gun, an effective tank destroyer in the Yom Kippur War (THE outstand antitank weapon, although, as a shock to the IDF, the soviet made "Sagger" wife guided missiles.
Turkey has upgraded some of their M-60's, I beleive, to carry a 120mm gun. I will try to find a Picture.
Many, sadly, have been "expended" as targets in the US.
I feel this is not a "mistake" as such, but the limited usefullness of the M-1A1's in "Urban combat" and the Usefullness of the well designed, armed, silent, and amored "Styker" Armored Cars (almost a light tank on wheels) does point to the possible need for more than just one "Tank Weight" in US services.
In reading several commentaries from gulf War I, it would appear that the M-60's fared well against the Iraqi operated Soviet T-72's.
It should be noted that this may have been due to better training abd, of course, the cross sharing of Information from the IDF in dealing with Soviet types.
The formidable "Centurion" Tank was upgraded from a 22lb gun (approximately 88mm) to the 105 MM (sorry I forget the exact 'type") Gun in British and israeli Service.
The Centurion had excellent 'grade climbing" and cross country performance.
What I am Suggesting is a Diesel Powered medium Tank Type for US service.
The Abrams is more than a bit of a gas guzzler. However, the British have been able to coax equivalent speed out of Perkins diesel equipped Heavy Tanks, notably Challenger I and II.
"All Enlightenment Gratefully Accepted"