  A widely discussed explanation for the origin of the X-ray emission observed
from knots in extended quasar jets with the Chandra X-ray Obseratory is
Compton-scattered CMBR by electrons with Lorentz factors $\gamma^\prime \sim
10^2$. This model faces difficulties in terms of total energy requirements, and
in explaining the spatial profiles of the radio, optical, and X-ray knots in
sources such as PKS 0637-752, 3C 273, or PKS 1127-145. These difficulties can
be resolved in the framework of one- and two-component synchrotron models. We
propose a model where the broad band radio to X-ray synchrotron emission in
quasar jets is powered by collimated beams of ultra-high energy neutrons and
gamma-rays formed in the sub-parsec scale jets. The decay of the neutral beam
in the intergalactic medium drives relativistic shocks to accelerate nonthermal
electrons out of the ambient medium. A second synchrotron component arises from
the injection of leptons with Lorentz factors $\gg 10^7$ that appear in the
extended jet in the process of decay of ultra-high energy gamma rays. This
approach could account for qualitative differences in the extended X-ray jets
of FR1 and FR2 galaxies. Detection of high-energy neutrinos from blazars and
core-dominated quasars will provide strong evidence for this model.
