The international system since the end of the Second World War has been founded on the equal legal sovereignty of states, non-interference in internal domestic affairs, and the preservation of existing territorial boundaries. Of course, juridical equality is perhaps less important that the practical inequality of states, and non-interference in domestic affairs is an increasingly scarce commodity. But the preservation of existing territorial boundaries has been the bedrock of the post-War system.
The incessant revision of boundaries had been the centerpiece of the Westphalian international order, and probably the chiefest defect, producing incessant warfare. Indeed, from 1648 to 1945, the practitioners of statecraft would have been largely at a loss to explain their aims apart from the re-drawing of maps. The notion that a state victorious in war was entitled to conquered territory in virtue of military victory was a recognized principle of international law. This conflict-prone legal regime ended in 1945, and while this did not produce perpetual peace, at least it provided one avenue for avoiding perpetual war.
Now this seems to be unraveling. The Russian appetite for "frozen conflicts" in Georgia and Transnistria was the beginning, now awfully magnified with war in the Donbas and the annexation of the Crimea. This last transgression was the source of extensive Western sanctions, so manifest was the violation of international norms. And these same legal norms effectively preclude "resolution" of this conflict, with Russia unwilling to restore its ill-gotten goods, and the West unwilling to ratify this patently illegal move.
As long as the Mappa Mundi is up for grabs, Turkey seems to be moving its southern border with Syria a few dozen miles southward, a supposedly temporary exigent of war with no evident path of return. An in India, the Modi government on 05 August 2018 revoked Kashmir's special status under Article 370 of the Indian constitution and divided it into two union territories.
In 1978, the Carter administration categorically concluded that Israel's establishment of civilian settlements was inconsistent with international law. However, in 1981, President Reagan disagreed with that conclusion and stated that he didn't believe that the settlements were inherently illegal. Subsequent administrations recognized that unrestrained settlement activity could be an obstacle to peace. And on 28 December 2016, Secretary Kerry publicly reaffirmed the illegality of the settlements.
On 18 November 2018 US Secretary of State Mike Pompeo announced Washington no longer regarded Israeli settlements in the West Bank as violating international law, reversing the Obama administration's position. Secretary Pompeo stated "the conclusion that we will no longer recognize Israeli settlements as per se inconsistent with international law is based on the unique facts, history, and circumstances presented by the establishment of civilian settlements in the West Bank. Our decision today does not prejudice or decide legal conclusions regarding situations in any other parts of the world."
But what is history, and what is world politics, other than a parade of "unique facts, history, and circumstances"? Every instance of land-grabbing in the past 75 years has witnessed such factors. Hopefully the present moment is a one-time reset of boundaries, but there can be no such safe assurance.