Indo-Pakistani tensions have been heightening over the last several months, but Sunday’s attack on an Indian army base in Kashmir that left 17 soldiers dead has put the region in crisis mode.

The attack took place near the Line of Control that divides Indian and Pakistani Kashmir and marks the most deadly attack against Indian security forces in over two decades. In 2002, a terrorist attack on an Indian army base in Jammu, Kashmir that killed over 30 (mostly family members of Indian army officials), nearly led to war between Pakistan and India.

Most of the casualties in Sunday’s attack were the result of fires that consumed temporary army shelters in the early morning hours during the grenade and gun attack. The four terrorists involved in the attack were killed in a gunfight that lasted three hours.

India is placing blame for the attack squarely on Pakistan, with Home Minister Rajnath Singh calling Pakistan a “terrorist state.” Following the attack, Singh canceled planned trips to Russia and the U.S. and called for an emergency meeting to study the situation.

Indian Prime Minister Narendra Modi said the attack perpetrators “would not go unpunished,” while Bharatiya Janata Party General Secretary Ram Madhav said India should take a “complete jaw for one tooth” and that “the days of strategic restraint are over.”

The attack follows over two months of civil unrest in Kashmir, sparked by the killing of a popular militant leader, Burhan Wani. The unrest has claimed the lives of nearly 85 Kashmiris, and Pakistan’s Prime Minister Nawaz Sharif had planned to highlight the regional tension and blame India for human rights abuses in his upcoming speech to the United Nations General Assembly scheduled for Wednesday.

A military response by India could include targeted strikes on terrorist training camps inside Pakistani territory, but such strikes would almost certainly lead to military escalation and potential all-out war. India would have to weigh the consequences of allowing the region to devolve into India-Pakistani conflict for India’s quest to be viewed as a rising and responsible global power.

The U.S. has forcefully condemned the attack but should go a step further to defuse tensions by calling on Pakistan to rein in terrorist groups operating freely on its soil. The fact that Pakistan has failed eight years later to prosecute the perpetrators of the 2008 Mumbai attacks belies its claims of not supporting cross-border terrorism.

The ball is in Pakistan’s court to immediately defuse tensions. Only concrete steps, like arresting militant leaders and shutting down training camps, will convince India (and the world) that Islamabad is serious about preventing its territory from being used for terror attacks against its neighbors.