Answer:
I can try: I suppose it is a bit like the reverse situation which brought about the Crimean war: Russia wants access to the Mediterranean Sea. Only in WW1 Turkey is the enemy of Britain & France rather than an ally. And so Anzac forces were sent to dominate a small peninsula which would prevent the Turks from dominating the seaway & allow ships to pass the Bosporus, or so the theory went. And theory was all it really amounted to, the practice was a disaster. The Turks were never dislodged from the heights and the invasion got nowhere very slowly, the generalship was very poor indeed and the costs very high. Strategically it was a very good idea but tactically it was inept.