the reader why BFKL dynamics is so interesting for QCD and why it is worth the considerable effort necessary to uncover it.

There are at least two important reasons why hard single scale high energy scattering is interesting. (i) It is a high energy scattering problem that may be soluble, or nearly soluble. (ii) BFKL evolution leads to high parton densities and thus into a new domain of nonperturbative, but weak coupling, QCD. As parton distributions evolve from a momentum fraction $x_1$ to a smaller momentum fraction $x_2$, all at a fixed transverse momentum scale, BFKL dynamics gives the rate of increase of those (mainly gluon) densities. This evolution is illustrated in Fig.7. When gluon densities reach a density such that on the order of $1/\alpha$ gluons overlap, perturbation theory breaks down and one enters a new regime of strong field, $F_{\mu\nu} \sim 1/g,$ QCD. While it is unlikely that one can reach such densities at Fermilab or HERA at truly hard transverse momentum scales one should at least be able to see the approach to these high densities through BFKL evolution.

Inclusive two-jet cross sections at Fermilab and forward single jet inclusive cross sections at HERA can be used 