Where would a new island most disrupt naval geography?

Where would placing a Guam-sized island create the greatest geopolitical disruption?

The suggestions include the Sea of Okhotsk, the Black Sea and the Strait of Hormuz, where location could provoke competition over access and control.

The scenario assumes an island appears without the usual geological process. The Peanut Hole in the Sea of Okhotsk is proposed because of the disputed interests described in the exchange. The account of UN decisions and maritime rights is not developed sufficiently to establish the area's legal status. A Black Sea location nearer Ukraine and Russia offers a different strategic complication. A position off Hormuz would affect an existing maritime chokepoint and is expected to draw an immediate response.