Initially there was a lot of British government propaganda
to inspire hatred for the Germans. Spurious stories of
German atrocities and 'frightfulness' were common.
Seemingly these had relatively little effect, since during
Xmas 1914 there were many instances of mutual
fraternisation in 'no-man's-land', inc. the odd game of football.
After the German use of gas during 'Ypres 2' and, later,
the shooting of Edith Cavell, British attitudes hardened
toward the Germans, but even so, this was patchy
among the British 'Tommies'.
There is credible evidence that following the German
'Spring Offensive' of 1918, and the 'Kaiserschlacht'
in the summer of that year, attitudes softened considerably
as Germany was patently losing the war, and this was
evident to both the Allies and the Axis.
One could argue that respect for the foe was never quite
lost from beginning to the end.
Respect for the French ? Well, that's another story.