It would have seemed implausible that, just eight months on, Mr Modi and Mr Xi would be meeting at an informal summit. But this is exactly what it is happening in the Chinese city of Wuhan, as the two leaders convene far from their capitals, without aides or an agenda, and plenty of time to discuss their mounting differences.
But the meeting does not come out of the blue. After the border dispute was defused in August, Mr Modi and Mr Xi broke the ice at the Brics summit in September, alongside the leaders of Russia, Brazil and South Africa.
A flurry of high-level visits to China followed, including by India’s foreign secretary, national security adviser, foreign minister and defence minister.
There were also some olive branches. In February, the Indian government sent out a private note asking officials to keep away from events marking the 60th anniversary of the Dalai Lama’s exile from Tibet. It quietly informed Beijing of this.
China considers the Dalai Lama a separatist and tries to isolate the spiritual leader by asking foreign leaders not to see him.
In March, Mr Modi followed up with fulsome congratulations to Mr Xi on his re-appointment as president, saying it showed Mr Xi enjoyed the “support of the whole Chinese nation”. In recent days,
China reciprocated. It will resume sharing hydrological data on the rivers that run into India and has offered to re-start low-level military exercises; both activities were suspended during last year’s crisis.
So why is this thaw occurring now? There are several reasons.
Firstly, India believes that last year’s crisis marked a dangerous phase in the relationship and that tensions need to be kept in check – especially with national elections in 2019. More broadly, China’s economy is five times bigger than India’s and its defence spending is three times as large.
While India has a local military advantage at many points on the border, it still needs time to build up its strength.
Secondly, India hopes to secure Beijing’s cooperation on several issues where China’s role is crucial, such as putting pressure on Pakistan-based terrorist groups and securing India’s admission to the Nuclear Suppliers Group (NSG), a body that controls nuclear trade.
In recent years, Indians have grown increasingly frustrated at what they see as Chinese efforts to thwart India’s rise, but Delhi has not given up on nudging Mr Xi in a more flexible direction.