How did the opening of Himalayan passes affect Nepal Valley during the Licchavi period?

During the Licchavi period (c. 450–750 ce), the opening of the Himalayan passes to the north of the Nepal Valley (now the Kathmandu Valley) was a transformative development.123

As a powerful, unified kingdom emerged in Tibet during this era, the newly accessible passes facilitated extensive cultural, trade, and political relations across the mountains. These connections effectively transitioned the valley from a relatively remote backwater into a major intellectual and commercial center linking South Asia and Central Asia. This period of connectivity also enabled the establishment of diplomatic contacts with China in the mid-7th century through the exchange of several missions, though these ties were eventually interrupted by intermittent warfare between Tibet and China.13