Islamabad faces increasingly difficult choices between defending Saudi Arabia and preserving ties with Iran, researcher Umer Karim says Weaker cooperation with Tehran could allow armed groups to exploit border vulnerabilities, analyst Arhama Siddiqa warns Principal danger is ‘a more unstable border, intensified insurgency Escalating Houthi attacks on Saudi Arabia are testing Pakistan’s ability to defend a longstanding security partner without damaging relations with neighboring Iran, with experts warning that deeper military involvement could carry consequences at home and across its borders. Islamabad’s dilemma brings together two relationships it has strong reasons to preserve – a defense and financial partnership with Riyadh, and cooperation with Tehran on border security, trade, energy and regional diplomacy. The Mecca Joint Defence Agreement, signed by Pakistan, Saudi Arabia and Türkiye on Aug. 7, treats an armed attack against one member as an attack against all three. This month, the countries agreed to implement their collective defense commitments amid attacks on Saudi territory.

“Pakistan cannot stay idle as it has committed itself to Saudi Arabia's defense,” Umer Karim, a doctoral researcher at the University of Birmingham, told Anadolu.

But defending the kingdom against the Iran-backed Houthis could undermine Islamabad’s efforts to deepen ties with Tehran and facilitate dialogue between Iran and the United States, he added. Balancing Saudi alliance with ties to Iran Saudi Arabia’s importance to Pakistan extends beyond military cooperation.

Riyadh has provided financial support to help Islamabad manage pressure on its external finances, including a pledge in April of an additional $3 billion finacial assistance alongside an extension of an existing $5 billion deposit.

Iran’s importance rests partly on geography.

The countries share a 909-kilometer (565-mile) border, making cooperation over militancy, smuggling and cross-border movement a practical security concern. Relations combine cooperation with recurring mistrust. In January 2024, the countries exchanged cross-border strikes against militant targets.

Both have nevertheless sought closer economic ties. In August, they agreed to expand trade, improve customs coordination, energy cooperation and activate joint border markets, pursuing a $10 billion annual trade target and a free trade agreement.

Christoph Bluth, professor of international relations and security at the University of Bradford, described Pakistan’s approach to Iran as pragmatic cooperation combined with strategic caution. Tehran was an important neighbor, he said, but not a strategic ally on the same level as Saudi Arabia or China.

The defense agreement could create friction without necessarily causing a breakdown in relations. “The decisive question is implementation,” he told Anadolu.

“If it develops into what is perceived as an operational anti-Iran or anti-Houthi coalition, it would seriously damage Islamabad-Tehran relations.”

Defensive support or direct involvement? Iranian lawmakers have criticized Pakistan’s growing military alignment with Saudi Arabia.

Iranian Foreign Ministry spokesman Esmaeil Baqaei expressed concern this month over reports of a possible large-scale Pakistani troop deployment, adding that he hoped it was only a "rumor." Bluth described Tehran’s response as divided. Some lawmakers had warned of retaliation if Iran were attacked from pact members’ territory, while the Foreign Ministry had indicated it did not presently regard the agreement as directed against Iran.

Pakistan’s leaders have sought to offer reassurance. President Asif Ali Zardari said Tuesday that the pact was “purely defensive and not directed against any country.”Prime Minister Shehbaz Sharif reaffirmed Pakistan’s commitment to Saudi security the following day.

Pakistan’s Foreign Ministry has also said its forces would defend Saudi territory rather than cross into Yemen to attack the Houthis. On Friday, it said that Pakistan has deployed a “substantial” number of military forces and resources in Saudi Arabia. Bluth considered participation in a ground war unlikely, with involvement instead potentially focused on air and missile defense, intelligence, training and protecting Saudi territory.

“Pakistan has agreed to provide rapidly deployable forces, but their numbers and precise mission remain undisclosed,” he said. “A defensive role would cause tension with Iran but could remain manageable,” he added.

“If it comes to direct operations against the Houthis, that would risk a major diplomatic crisis.”

Karim said Pakistan’s existing military presence in Saudi Arabia demonstrated its commitment to Riyadh.

“Pakistan's military is already on the ground within Saudi Arabia, which signifies Pakistan's resolve to stand by its Saudi ally,” he said. "It's only a matter of time that it will become whether directly or indirectly involved against Houthis," he said. According to him, the Iranian side clearly does not view this positively and "is likely to express its disappointment mainly through unofficial channels and also by mobilizing pro-Iran constituencies within Pakistan."

Arhama Siddiqa, a research fellow at the Institute of Strategic Studies Islamabad, emphasized the distinction between defensive cooperation and offensive operations. “Pakistan has clarified that the agreement is defensive and does not envisage cross-border operations against the Houthis in Yemen,” she told Anadolu.

Instead, Islamabad has an interest in encouraging restraint and a negotiated settlement to prevent wider conflict and preserve constructive relations with Iran, she added. Border security, economic risks The experts differed over how deteriorating relations with Tehran would affect Pakistan.

Karim argued that security conditions had already worsened on both sides, limiting the additional impact of a diplomatic downturn.

He also expected relatively limited consequences for energy cooperation because economic links remained weak. Bluth, however, warned that strained relations could weaken intelligence-sharing and border management, giving armed groups greater room to operate across the frontier between Pakistan’s Balochistan and Iran’s Sistan-Baluchestan provinces.

“It could also aggravate sectarian tensions inside Pakistan,” he said.

Border commerce, local livelihoods and Iranian electricity supplies could suffer, alongside prospects for the Iran-Pakistan gas pipeline and wider energy cooperation.

The principal danger, Bluth said, was not conventional war but “a more unstable border, intensified insurgency and increased security risks for Pakistan.”

Siddiqa similarly warned that weaker cooperation could allow non-state actors to exploit vulnerabilities, while disrupting trade, border markets, connectivity and energy projects. “The two neighbours face common challenges relating to cross-border terrorism, militancy, smuggling and border management, making sustained security coordination indispensable,” she said.

Neither country would benefit from further border instability, she added, stressing the importance of maintaining diplomatic and institutional contacts.

Pakistan’s mediation role at risk Pakistan’s role in brokering talks between Tehran and Washington, which led to the Islamabad Memorandum in June, gives it another reason to preserve relations with Iran.

Islamabad has served as an intermediary between the two sides, and Pakistan’s Foreign Ministry said Iran reaffirmed its trust in Islamabad’s mediation during President Masoud Pezeshkian’s June visit.

But Karim said those diplomatic efforts were increasingly in conflict with the security demands arising from Houthi attacks and renewed fighting in Yemen.

Bluth argued that mediation did not require complete neutrality. Iran’s continued willingness to exchange messages through intermediaries, including Pakistan, suggested that trust had not entirely collapsed.

“Pakistan must keep its Saudi commitment restricted to defensive measures, maintain direct consultation with Tehran and support political engagement with the Houthis,” he said.

“If Pakistani forces participate in direct offensive operations against the Houthis or Iran, it is unlikely it can sustain its role as mediator,” he added.

Siddiqa said the defense cooperation did not inherently contradict Pakistan’s role as a facilitator. Effective mediation, however, depended on maintaining trust, credibility and open communication.

Karim was more pessimistic that Pakistan could act as a mediator while also engaging in the Yemen conflict. “It will be extremely difficult, and eventually Pakistan will have to choose one side,” he said.