What were the causes of the "Dardanelles" fiasco in World War I

The Time lag between the initial naval operations in feb/march and the landings in april telegraphed a probable landing and gave the turks time to reinforce the area.

Why didn't the allies use over routes to Russia, I would say the poor state of Russian railways and their overloaded state was a factor (I doubt there was an effective Persian railway in ww1, for that route to be used in ww2 a major upgrade of the works was rehired)

Archangelsk: they did use this route to supply Russia. The main problems were that it was only open during the Summer and even in the Summer it is dangerous for ships.

Persia: This was not a viable route in 1916 due to a lack of railroads.

Trans-Siberian Railway: This very long route was used during the war, however, it was unreliable and the British did not have good access to Vladivostok, the port of entry. After the US entered the war, large amounts of American loaned equipment was sent to Vladivostok, but the Russian administration had serious organizational and financial problems that prevented them from utilizing the equipment effectively. Much of it piled up in warehouses and depots in Siberia.

The attack on the Dardanelles was not just about getting access to Russia, it was also an attempt to cut off Turkey from Austria-Hungary. Most British generals were focused on the war in France and did not want to divert resources from that fight which they considered more important.

The original concept was a gamble. The dice roll came up snake eyes. But it was stupid pride that turned a bad beat (one could argue that it was bad luck, or astute placement, that the Nusret managed to lay a line of mines that ended the naval campaign) into a slaughter.

The root cause of the whole thing was Winston Churchill.

Churchill was a gambler. I actually didn't know this. I typed it in before I googled for it (https://www.telegraph.co.uk/books/what-to-read/no-more-champagne-churchill-and-money-david-lough-review/). But if you look at Churchill's life and career, it seemed like a reasonable guess.

Gallipoli was no different.

It was an audacious gamble: high stake, high risk (with a very low chance of success), but potentially very high reward.

One could argue that the original concept was brilliant, take a bunch of old battleships not fit for combat against the High sea Fleet and sail them up the Dardanelle, through the sea of marmara, into Istanbul, and force the surrender of the Ottoman Empire.

But the strategic importance of the Dardanelle was so self explanatory to all, it has been heavily fortified for centuries and centuries.

So the brilliance of the original concept was entirely a matter of whether you share Winston's passion for gambling or not.

The challenge to the strike fleet of nearly a 100 ships with over 30 capital ships was, it must traverse 36 miles through the Dardenelle, a narrow and heavily mined stretch of water between .75 and 4 miles wide with Ottoman forts on both sides.

The fleet never actually got very far. While the mass of heavy entente naval firepower did demolish some ottoman forts at the mouth of the strait, they were never able to silent the guns harrying the minesweepers. So when the entente lost 6 battleships (3 sunk 3 headily damaged) on march 18, 1915, the officer in charge, John de Robeck, called off the attack.

Winston Churchill wanted to double down and sent more ships to replaced the lost vessels, but the renew attack never happened.

It is worth noting that the anglo-french fleet never even breached the first line of the 10 layers deep mine field.

It should also be noted that even if they could breach that, there was nothing to say that the ottoman could not simply set up more mines and prepare more guns further up the strait.

And it should be further noted that even if all that happened and the battered fleet reached Istanbul, there was no guarantee at all that the ottoman would simply surrender to a naval fleet with no ground troops. And there was nothing to say that the Ottoman couldn't close the straight back up, and trap the whole invasion fleet in the sea of Marmara.

So conceptually, a naval attack up the Dardanelles was an ill considered gamble that didn't pan out.

But the true tragedy comes after the initial failure to force the Dardenelle by sea.

After that it was decided that the strait couldn't be breached without securing the land side first.

A reasonable observation, but now the Entente was just double downing on a weak trash hand.

And what followed was 9 months of pointless slaughter, with ANZAC forces trying to take the ottoman hills overlooking the landing beaches. One side had superior naval firepower, but the other side had geography (the mythical high ground)...

The causes of failure were pride, stupidity, a passion for glory, and an obstinate refusal to admit defeat.

The Dardanelles campaign was as much about resupplying Russia as knocking the Ottoman Empire out of the war by taking the capital, Istanbul. It's also easy to say in retrospect that not enough soldiers and ships were sent to that theatre, but at the time the commanders evidently thought they had enough. Calling the effort "half-baked" only makes sense with the luxury of hindsight. A better question could be why didn't the Allies land at the poorly defended beaches west of the Dardanelles and then take them from an established position?

To take up your suggestion that the Allies were undermanned, you should remember that they actually outnumbered the Ottoman troops sent to defend the Dardanelles. Although the ANZACs (Australia and New Zealand Army Corps) are most famous for having fought in the Dardanelles Campaign, there were actually more soldiers there from Great Britain, France and their colonies.

It is understood by historians that the Allied powers under-estimated the amount of resources the Ottoman Empire had put into the defence of the straits. The Allies also underestimated the quality of the Ottoman soldiers, even though many of these were veterans of the two Balkan Wars and the Ottoman-Italian war in Libya. In Australian and New Zealand histories, the commanding British officers were to blame for mismanaging the landings. In Turkish historiography, the leadership of Mustafa Kemal (later Atatürk), in tactics and in galvanising the Ottoman troops to defend their homeland, is emphasised. Moreover, the Ottoman Empire was basically battling for its very survival at Gallipoli, unlike their involvement on the other fronts.

Finally, the terrain surrounding the Dardanelles is very much conducive to a defensive position, with hills looking down on the beaches and effective points to place guns. The narrow straits also meant that Ottoman mines could effectively disrupt naval assaults through the passage.