In 1939, a Japanese Railway official, Yumoto Noboru, wrote of a trans-Eurasian railway to link Japan to its Axis partner, Germany, and proposed the construction of an undersea tunnel to connect Japan with Korea via the island of Tsushima.[11][12] It was argued a combined undersea tunnel and land link would help safeguard Japanese communications and shipments to and from Europe, which would be imperiled by a Pacific War.[Note 1]