A still frame from the Google Web ad, "Reunion." (YouTube)

If you are from South Asia, have family from South Asia, or are merely friends on Facebook with someone who has ties to the subcontinent, you've already seen this video posted to social media in the 48 hours since it went up. In case you haven't, it's a Google advertisement, about three and a half minutes, well worth your time.

Yes, it's an ad, meant to prod people in one of the world's largest markets into using Google services. And in that context it can be a bit syrupy. But take a step back for a moment, and try to appreciate what makes this video so powerful that it's already been viewed 1.8 million times:

The 1947 partition of Britain-colonized India into India and Pakistan was one of the most traumatic events of post-World War II history, tearing apart countless communities as families fled across the new national borders. That trauma, and the pain of its memory, is reflected in the emotional force of this video.

The 1947 partition was, as Armin Rosen wrote in a worthwhile photographic retelling of the event, "a social, historical and geographic wound that has yet to fully heal." Pakistan (which later divided again, into Pakistan and Bangladesh, in 1971) was to be the nation for Muslims; many Indian Muslims believed they would only be safe in that new country, while many Hindus and Sikhs in what was to be Pakistan fled for the new, smaller India. Up to 17 million people were displaced by the partition, one of the largest migrations in human history, and as many as a million died along the way.

Since 1947, India and Pakistan have fought four wars, and come dangerously close to nuclear conflict. Tensions between the two countries remain some of the highest in the world.

But what this video shows is the human cost of dividing what would today be the world's most populous society had it not split, as well as the hope of, not exactly a national reunion, but a cultural one.