[davem]

'Then if the Ring cannot be kept from him for ever by strength,' said Glorfindel, 'two things only remain for us to attempt: to send it over the Sea, or to destroy it.' 'But Gandalf has revealed to us that we cannot destroy it by any craft that we here possess,' said Elrond. 'And they who dwell beyond the Sea would not receive it: for good or ill it belongs to Middle-earth; it is for us who still dwell here to deal with it.' (Council of Elrond)

I think it is clear that it cannot be sent over the Sea from Elrond's words given here. It seems plain that the Straight Road was not simply open for all comers - even Elves. They might be permitted to return, but only in certain circumstances - with the Ring would not be one of them.

In other words, its not the case that any Elf (even any High Elf) could just hop into a ship & go back - they would have to be allowed in. Elrond states the Valar would not receive the Ring - it belongs to Middle-earth. This is clearly the point. the only place it can be destroyed is in the fires of Orodruin, the place it was made. Hence, even if it could be taken into the West it could not be destroyed there. If it could not be destroyed Sauron would continue to exist & he had already all but won victory. If the Ring was in the West it would be unassailable, Sauron would be invincible & his victory would be guaranteed permanently. The very worst thing that could be done with it would be to remove it to a place of safety. And of course, there's no reason to believe it would not work on the Elves (& Maiar) in the Blessed Realm & bring disaster there too.

Elrond's words are interesting 'For good or ill..' he says. My reading is that he is saying that it is actually a good thing that the Ring remain in Middle-earth because while there it can be destroyed, & if the worst comes to the worst, only Middle-earth is in danger, & Sauron's malice will be contained in Endor.

Whatever. The Ring cannot be taken into the West as the Valar will not allow it to be. If it was cast into the depths of the Sea it would still exist, & therefore so would Sauron, & hence he would win, because he is far more powerful than his opponents. Sauron des not need the Ring to achieve victory - which is already assured - the only thing that can defeat him is its destruction & the only place it can be destroyed is the place of its forging - in Middle-earth.