Cosmic rays of energies larger than the Greisen-Zatsepin-Kuzmin cutoff may
be neutrinos if they acquire strong interactions due to a "precocious unifi
cation" of forces. A scenario for this to happen is outlined. There is no c
ontradiction with precision measurements carried out at LEP and SLAC. Obser
vable consequences at LHC and future neutrino detectors are discussed. [S00
31-9007(99)08453-7].