The speed of light through a vacuum is about 300,000 km/s. The speed of light over a fiber optic cable is about 200,000 km/s. The distance between, say Singap

The speed of light through a vacuum is about 300,000 km/s. The speed of light over a fiber optic cable is about 200,000 km/s. The distance between, say Singapore and New York, is about 15,000 km. If we pretend the cable runs all the way to the East Coast, this gets us to 0.075 seconds for light to travel that distance around the Earth over fiber. So that's a theoretical minimum of 75 milliseconds additional lag in addition whatever network equipment exists in between you and your friends. Actually not too bad, even though we concede that the premise is slightly absurd.