Reuters cannot find Sanremo on the map

In addition to being a lovely holiday resort on the Italian Riviera, Sanremo is the spot where Allied Powers of World War I met in 1920 to disposition (not really a verb but apropos here) the territory of the vanquished Ottoman Empire.  The resolution arising from the San Remo conference called for the recognition of sovereign states of Syria and Mesopotamia (modern-day Iraq) and a Jewish national home in Palestine.  It mandated that:

The Administration of Palestine, while ensuring that the rights and position of other sections of the population are not prejudiced, shall facilitate Jewish immigration under suitable conditions and shall encourage, in co-operation with the Jewish agency referred to in Article 4, close settlement by Jews on the land, including State lands and waste lands not required for public purposes.

The San Remo resolution became international law on July 24, 1922 when it was adopted by the League of Nations and subsequently grandfathered across to the League's successor, the United Nations. 

In 1947, the British abandoned their responsibility as Administrator of the Palestine Mandate and the UN recommended partition of the remaining land (78 percent had already been given away to the Hashemite Arabs) between Jews and Arabs living west of the Jordan River.  The Arabs violently rejected partition and the rest, as they say, is history.

For Tom Perry and the babes at Reuters however, history only begins in 1967:

Israel has settled the territory extensively since 1967, when it captured and occupied the West Bank and the Gaza Strip. The international community for the most part deems the [Jewish] settlements illegal. 

Settler leaders claim a biblical right to the West Bank.

It is undoubtedly true that many Jewish settlers in Judea and Samaria (the "West Bank") feel the 3,500 year history of Jewish civilization and culture in the territory, as documented in both the Bible and the archaeological record, well-qualifies them to live there.  At the end of the day however, it is contemporary international law, embodied in San Remo and still on the books at the United Nations, which guarantees that right.