What are the ramifications of the British and the French not attempting to force the Dardanelles?
The reputation of Winston Churchill is not damaged. He does not leave the cabinet (although i suspect the Conservatives would have had him out as a condition of joining the Asquith coalition), I wonder what that means for both Churchill and us? Perhaps no wilderness years, perhaps PM sooner, perhaps no Churchill in 1941 etc.
The Anzac troops are not killed there in large numbers perhaps having an impact on what has been described as the beginning of Australian and New Zealand national consciousness ( although i suspect those loyal empire troops would have just as easily been slaughtered in France as the Canadians & Newfoundlanders were) and a lingering distrust of Britain and the delayed fracturing of the allegiances of empire from our antipodean cousins.
I suspect that Churchill and others would have looked for another landing spot on the "soft underbelly of Europe" ( to coin a phrase) because they wanted to get out of the circle of death in France and Belgium.