Isolation is a pervasive element that is often used as explanation for Othello's breakdown, as he is isolated socially, geographically, and mentally throughout the course of the play. Isolation serves as the catalyst for the deterioration of love.
Othello faces social isolation as a result of his race - though he holds the position of General, he is still referred to as "The Moor" by many, whether they 'respect' him or not, and his race is also weaponised against him when other characters believe him to be immoral. As the only black man in a cast of white characters, from the moment we meet him Othello has already been isolated from the rest of the cast.
Othello faces geographical isolation in the form of the move from Venice to Cyprus. He specifically moves to Cyprus in order to continue fighting in the war, and so this location is thereby symbolic of violence and brutality - whilst Venice in comparison is held as a paragon of civility. HOWEVER, Cyprus is entirely protected from external forces due to nature and military fortifications, so this means that the "violence of Cyprus" thereby has nowhere to manifest other than within our characters. Cyprus is also an island, making it further isolated from the outside world.
Othello is isolated mentally by way of Iago, as he becomes the only character Othello truly confides in towards the end of the play. He doesn't share his thoughts with Desdemona or Cassio, making him isolated from his loved ones. In the end, Othello's choice to murder Desdemona appears to be entirely out of character to everyone other than Iago, making him further isolated as no one is able to even comprehend his thought process.