Just out of interest, was the MiG-25 'all steel' and 'all valves'? As in no electronics as we know them, just valves? I had heard that it was EMP-proof due to the lack of any transistors on board...
80% nickel steel alloy, 11% aluminium, and 9% titanium. Using valves instead of transistors meant for easier maintenance in addition to resistance to EMP. [0]
[0] http://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25