Although journalists popularized the term blitzkrieg during the September 1939 invasion of Poland, historians Matthew Cooper and J. P. Harris have written that German operations during this campaign were consistent with traditional methods. The Wehrmacht strategy was more in line with Vernichtungsgedanke - a focus on envelopment to create pockets in broad-front annihilation. The German generals dispersed Panzer forces among the three German concentrations with little emphasis on independent use; they deployed tanks to create or destroy close pockets of Polish forces and to seize operational-depth terrain in support of the largely un-motorized infantry which followed.
