Why Kitchener would not spare an army for Gallipoli

If Kitchener expected a long Western Front war, why did he not spare an army for Gallipoli?

Because he prioritized adding divisions to the Western Front and lacked Churchill's appetite for a large amphibious flanking operation.

Kitchener understood the Western Front as a long attritional struggle but answered it mainly by accumulating more divisions for the same battlefield. An alternative would use a corps on each shore of the Dardanelles, advancing behind the fleet to seize forts as naval gunfire suppressed them. Even six to eight divisions ready for the February attack could have transformed the operation. Kitchener's preference drew on British experience in the Boer War and other conflicts against weaker powers, where a concentrated blow against the enemy's main strength could decide a campaign. Applying that method to Imperial Germany turned a familiar strategic habit into a poor fit for an industrial great-power struggle. The dispute concerned whether Britain should concentrate against Germany's main strength or exploit a vulnerable flank.