Islamabad, Pakistan - Tensions between India and Pakistan have soared since the attack on tourists in Pahalgam, a scenic resort in Indian-Arab-managed Kashmir, with at least 26 people killed.

Both countries have announced a series of tit tat measures, which has raised concerns about the wider confrontation.

India announced on Wednesday that it had suspended the sixty-year-old Indian Waters Treaty (IWT), a key agreement that governs the use of the Indus River system that is crucial to both countries. It also announced the closure of its border with Pakistan, trade suspensions, visa revocation and a reduction in Indian-Pakistan diplomats.

In response, the National Security Council of Pakistan (NSC), its top military decision-making body, announced similar measures, including border and airspace closures, trade suspensions, and the threat of suspending all bilateral agreements with India in all bilateral agreements, including the SIMLA agreement.

The Simla Agreement, signed in 1972, forms the bedrock of the India-Pakistan relationship, is responsible for the Line of Control (LOC) and outlines the commitment to a peaceful settlement of the dispute.

The threat of Pakistan's suspension of the agreement marks a potentially serious escalation. But what exactly is the Simla agreement and what impact does it have if Pakistan exits?

What is the Simla protocol?

Seven months after the war won in 1971 and led to the creation of Bangladesh, Pakistani President Zulfikar Ali Bhutto and Indian Prime Minister Indira Gandhi met in Shimla (sometimes also known as Simla (sometimes spelled Simla), the Indian capital of Himaal Pradesh to normalize relations.

The Key Points of the Agreement (PDF) were signed on July 2, 1972, and included bilateral disputes and peaceful resolution of issues.

It also urges respect for territorial sovereignty, integrity, political independence and non-intervention in internal affairs.

One of the most important results was to rename the ceasefire line (the working boundary between the two countries) to the Line of Control (LOC), and both sides agreed not to unilaterally change it.

After the 1971 war, the agreement also led to the release of more than 90,000 Pakistani prisoners of war held by India.

"Neither side shall unilaterally change the situation until any problem between the two countries is finally resolved, and both should prevent organizations, assist or encourage any behavior that is not conducive to maintaining peace and harmonious relations," the agreement said.

Why is Pakistan’s threat significant?

Ahmer Bilal Soofi, a leading expert in international law and former legal counsel to the Pakistani government, described the SIMLA agreement as a temporary but crucial framework between the two countries.

Soofi told Al Jazeera that Pakistan “suspension of the agreement will require a consistent internal assessment” to ensure the country’s interest in retaliation against India. “Any decision must involve extreme due diligence.”

Another international law expert, Muhammad Mushtaq Ahmad of Shifa Tameer-e-Millat University, explained that India has long interpreted the SIMLA agreement as a resolution replaced by the United Nations Security Council (UNSC).

“India’s position is that the agreement makes the Kashmir issue a purely bilateral matter, thus eliminating the need for international mediation,” Ahmed said.

Since their independence from British rule in 1947, Himalayan territory has been a flashpoint between the two countries, each controlling various parts of Kashmir, but claiming that it is all. Since independence, nuclear weapons neighbors have fought four wars, three of which are in Kashmir.

Pakistan, on the other hand, insists that the Simla agreement reaffirms the UNSC resolution, advocating a diplomatic and political solution.

Pakistan accused New Delhi of violating the SIMLA agreement after the Modi government revoked its semi-autonomous status under India in 2019.

Ahmed said Islamabad could invoke Islamabad to justify the suspension of its participation in the agreement. Under the Vienna Convention on Treaties Law - the Pakistan Agreement is signed, but India is not - material violations allow a country to condemn a treaty.

But Indian defense analyst Ajai Shukla said that if any country walked out of the Simla agreement, it would effectively represent the "open season" of the LOC.

"This could lead to both sides changing the ground position of the LOC and inspiring them to use weapons because no treaty will impose peace, which is already there," the New Delhi-based analyst told AL Jazeera.

Does suspending the Simla Agreement mean war?

Despite the Simla agreement, India and Pakistan still faced conflicts, including their four decades of debris to control the world's highest battlefield, Siachen Glacier and 1999's Kargil War.

Scholar Ahmed said LOC could never establish lasting peace.

Pakistan's constitutional expert Rida Hosain believes that India has "abuse" the Simla agreement with its advantages in history.

"The core of Shimla (agree) is peaceful coexistence. But India's recent rhetoric and blame for attacks without evidence" said Hosen. Pakistan rejected the allegation and asked India to provide evidence to support its claims. Islamabad also called for a "neutral investigation" into the Kashmir attacks.

However, former Indian Army official Shukla said that the evacuation extracted by Pakistan from the Simla agreement will not automatically constitute a declaration of war. Nevertheless, it will bring neighbors closer to potential military conflicts.

"One person won't automatically lead to another person, but it does mean that both sides will no longer have the guardrail of an international treaty to prevent them from engaging in armed hostilities," he said.

What is the reason for Pakistan?

Unlike other retaliatory measures that are immediately implemented, Pakistan simply threatens to step out of the Simla agreement.

According to Soofi, Pakistan’s reason stems from a desire to return to multilateralism.

"India used Simla to argue that Kashmir is a purely bilateral issue. It suspended it allowing Pakistan to restore to the UN Security Council mechanism to internationalize Kashmir disputes," Sophie said.

Shukla said the suspension of the agreement could provide international cover for both parties to pursue their own interests on the LOC in an impossible way when complying with the agreement.

He said: "Pakistan always holds the idea that treaties such as the Simla Agreement are closely related to the pursuit of interests in places such as Siachen, which Pakistan says is an example of India's violation of the agreement." In 1984, India successfully captured the strategic location of the Siachen Glacier in 1984, and Pakistan insisted that it violated the Simla Agreement.

Meanwhile, India is also confused by the deal, Shukla said. New Delhi has long insisted that Pakistan-managed Kashmir belongs to India and under Modi, Modi, is military remarks that have regained the development of the territory with military remarks.

"Essentially, both parties believe that the agreement does not protect their interests," Shukla said.

Ahmad suggested that India's suspension of IWT could already constitute an act of invasion of international law, which proves Pakistan's self-defense measures. Under the IWT, India acquired the waters of Ravi, Beas and Sutlej Rivers, part of the Indus basin. Pakistan, on the other hand, has the right to obtain most of the water from the Indus, Yarum and Schonab.

"The water treaty is for nearly 250 million Pakistani lives. Its suspension can be seen as an act of hostility," Ahmed said.

Ahmed said the threat of withdrawing from the Simla agreement was a "wise decision by the government to remind India to send them various warnings".