I forgot to mention this earlier, but one of the big issues of Palmerston's time as Prime Minister was the question of support for Denmark in the Second Schleiswig-Holstein War. There was significant public support for intervention to protect Denmark, but Palmerston determined not to intervene - in no small part because the British Army was not (and could not be expected to be) enough better than the Prussians and Austrians to overcome the fact there were nearly a million German troops available and Britain could not deploy much more than 100,000 to fight on the continent.I do wish there could be even a slight concession about Palmerston's political stature during this period. His inability to move Britain to more active support for the Confederacy was a consequence of the public and Parliament's memory regarding embarrassments of Crimea and India. That the public was wrong about what had gone wrong in those military adventures is conceded; the British voters were as ignorant as some of my own comments about weapons and marksmanship have been, but that ignorance did not change the direction of public opinion.
During the Trent crisis, meanwhile, Palmerston elected to allow for an olive branch (and last chance for peace) rather than go straight to war, but this was driven by a genuine desire for peace rather than a lack of support for war. We know this because all the indications we have available from the period indicate that the Trent crisis was something that the British public would support as a casus bellum.
The idea that the public and Parliament thought the British armed forces (including the Army) were subpar on a man for man basis is not supported.