Source: Doctrine of graduated escalation - (The Hindu)
What is meant by the bold part here
Every time a Pakistani leader wishes to build better ties with New Delhi, his effort is undermined by the military masterminding a serious cross-border attack or terror strike. Indeed, it was during Mr. Sharif’s previous stint in office that a major Indian peace initiative — as symbolised by then Prime Minister Atal Bihari Vajpayee’s bus diplomacy — collapsed spectacularly, with the bus itself getting hijacked allegorically to Kargil, triggering a war.
(Kargil is a place where India-Pakistan war of 1999 was fought)
I looked up a dictionary but I can't understand its meaning here. Please explain to me.