Nobody is more vunerable to EMP than the US. Radiation and EMP resistant chips, memory, processors, Gate arrays, etc have been available since the late 80s in the good old USA. Till now, the military been the best customer.
We have elaborate infrastructure though and some crucial parts are not EMP shielded( in fact EMP is scary enough to me that I may break from my usual libertarian views on things and advocate the FedGov require all crucial infrastructure EMP shielded).