Analysts are generally skeptical at present of reports Pakistan and Russia are engaged in negotiations for the delivery of a number of Su-35 Flanker E fighter aircraft, though there is a potential requirement for such a heavy fighter.
The reports, first published in Russian media, cited Russian Deputy Foreign Minister Sergei Ryabkov as saying both sides were negotiating for the delivery of an unspecified number of Su-35 jets alongside the Mi-35M "Hind E" helicopter gunships that have recently been agreed upon.
However, no word on any such negotiations was received from the Ministry of Defence Production in Pakistan when asked for comment on the issue. The agency also handles acquisition.
Experts are generally skeptical of any Su-35 being acquired by Pakistan.
Author, analyst and former Australian defense attache to Islamabad, Brian Cloughley, said he "would be most surprised if there were to be any arrangement for provision of Su-35s."
"The Indians would be extremely upset, to the point of a major diplomatic rift," Cloughley said.
Though India is actively seeking to diversify its source of equipment from reliance on Russia, and the latter is seeking a new customer that includes limited defense sales to Pakistan, the Indo-Russian relationship is still very strong as evidenced by the co-development of the next generation PAK-FA stealth aircraft.
Analyst, author and former Pakistani Air Force pilot Kaiser Tufail is also unconvinced at present that negotiations for the Su-35 are actually underway.
"To me it seems more like an offer by the Russians, more than anything else," he said.
Many analysts have considered the current Pakistani plan to carry on investing in the JF-17 Thunder program, and acquire further new or surplus F-16s if possible, to be the optimal way of modernizing its air power as well as reducing combat types. A role for such a heavy fighter as the Su-35 has not generally been envisioned.
However, Tufail says there is a possible need for something in this class on two accounts: diversification and to support naval operations.
The Su-35 "being a twin-engined aircraft with vast range (and endurance), it would help us to have a significant and potent presence in the Arabian Sea, something that the puny, aging Mirage squadron is ill-suited for (as is the JF-17 from the range point of view)," he said. "Given the changing geo-politics and the Chinese investment whose trade terminus is Gwadar, there is definitely going to be a need for a long-range fighter. So essentially, I see it as a guarantor of maritime security as far as the airspace is concerned."
Pakistan has never operated such a twin-engine fighter aircraft, but Tufail says this has been a shortcoming.
"This has been a yawning gap in [the air force's] capabilities. These fighters would also allow unhindered patrolling by the naval [long range maritime patrol aircraft], as well as providing top cover to our fleet at sea," he said.
He does not see this as a departure from the established defense posture, but recognition of an existing shortcoming.
"All of this may sound like a sudden switch from continental strategy to a maritime one, but it is high time that we paid serious attention to this aspect in the fast changing geopolitical scenario."
Pakistan's air power over the Arabian Sea already received a boost this month when No. 2 'Minhas' Squadron based in Karachi was re-equipped September 6 with the JF-17 Block II after surrendering its Chengdu F-7P fighters.
Speaking at the time, Tufail said this was overdue: "The re-equipment of [No. 2 'Minhas' Squadron] was due as they had the oldest lot of F-7s. The JF-17 was the obvious replacement."
However, he did not believe it would take over the anti-shipping strike role from the Mirage 5, which he flew during his air force career, even though the JF-17 can carry the C-802A/CSS-N-8 Saccade or the supersonic CM-400AKG.
"This, however, does not necessarily imply that it will immediately take over the maritime attack role. The Mirage-5PA2/3 is still a capable aircraft, though long in the tooth by now. Most likely, the replacement of these Mirages would have a maritime role, so it could be a couple of years before we see a newer capability," he said.
Whether that replacement is the Su-35, however, remains to be seen.