The story so far:

On September 14, 2026, U.S. Air Force secretary Troy Meink said the country has “space control” weapons deployed in Earth’s orbit to defend U.S. forces against “hostile adversary action”. The disclosure drew backlash from Russia and China, among other quarters.

What is a ‘space control’ weapon?

As per the U.S. Space Force, ‘space control’ refers to military activities required to control the space domain. In 2025, the then-Space Force chief, Gen. Chance Saltzman, said such a device could possess both “kinetic and non-kinetic” capabilities and could disrupt or degrade an adversary’s capabilities.

‘Kinetic’ generally refers to physically damaging an object through impact, such as by smashing into it. Non-kinetic methods include electromagnetic interference that can jam or spoof a satellite’s communications, and directed energy systems that interfere with its sensors.

In fact, the current Space Force war-fighting framework recognises three kinds of counter-space operations: orbital, electromagnetic, and cyberspace.

What has the U.S. deployed?

We do not know. We also do not know how many units/instances of the system exist, what they are capable of, which orbits they are in, and whether they are kinetic or non-kinetic. Mr. Meink had said that while disclosing the weapon’s (or weapons’) existence would contribute to deterrence, revealing their operational details would subtract from the deterrence. There is also no indication whether these weapons are the same as the space-based interceptors the U.S. government has planned for the ‘Golden Dome’ missile defence programme. These interceptors are still undergoing tests.

What will the weapons defend against?

Mr. Meink has referred to “hostile adversary action”. Incumbent Space Force chief Gen. Douglas Schiess has also referred to “space-enabled attacks”.

In other instances over the years, U.S. officials have repeatedly singled out Russian and Chinese counter-space capabilities as reasons for their government to develop similar capabilities of its own, to protect its own satellites. Russia and China have also demonstrated sophisticated satellite manoeuvres in orbit.

For example, in 2020, two Russian satellites manoeuvred close to a U.S. government satellite, prompting the Space Command to call the behaviour potentially threatening. In 2022, the Chinese Shijian-21 satellite used a robotic arm to tow a defunct Chinese geostationary satellite into a graveyard orbit.

However, we do not know the circumstances in which the U.S. will use its weapons as the government has not published the rules of engagement for orbital weapons.

Is it legal to have weapons in orbit?

The relevant instrument is the Outer Space Treaty, which entered into force in 1967, during the Cold War and the nuclear arms race between the U.S. and the Soviet Union. It prohibits its party states, which include the U.S., Russia, and China today, from placing nuclear weapons or other weapons of mass destruction in orbit or stationing them elsewhere in outer space. It also obviates states from setting up military bases and conducting weapons tests on the moon and other celestial bodies.

However, the treaty does not prohibit states from placing conventional weapons in orbit. The treaty also says all activities in outer space must comply with international law, which means other bodies of international law governing the use of force and armed conflicts can be applied to military operations in orbit. As the U.S. government has not disclosed what its orbital weapons are capable of, it is not possible to say whether it violates specific treaty conditions.

Can other countries prevent unilateral action?

There is no international body to order the U.S. to remove its weapons from orbit. However, there are various diplomatic and legal avenues through which other countries can seek more information and negotiate restraints. For example, Article IX of the treaty requires states to have “due regard” for the interests of other parties, which a (party) state can invoke if it believes U.S. activities in orbit could harm its own peaceful use of space. States can also endeavour to draft new orbital governance rules through the United Nations process on the Prevention of an Arms Race in Outer Space, whose third substantive session is scheduled for November. Countries can also raise the issue before the UN Security Council or the General Assembly as a threat to international peace and security, under Article 35 of the UN Charter.

The story so far:

A Pakistan Navy vessel, PNS Hunain, collided with an Indian Navy warship, INS Kolkata, in the North Arabian Sea on September 15 after, according to India, the Pakistani ship made a dangerous overtaking manoeuvre at high speed. India summoned Pakistan’s Charge d’Affaires and cited violations of Article 10 of the 1991 India-Pakistan agreement, which requires naval vessels to maintain separation of three nautical miles. Pakistan rejected India’s allegations. INS Kolkata suffered no major damage and remains at sea. PNS Hunain was damaged and subsequently returned to harbour.

What are INS Kolkata and PNS Hunain?

The two vessels involved are different classes of warships. INS Kolkata is the lead ship of the Indian Navy’s Project 15A Kolkata-class guided missile destroyers. Built by Mazagon Dock Shipbuilders in Mumbai, the 164-metre-long warship has a full-load displacement of about 7,400 tonnes and is capable of sailing at 30-knot speed. It was commissioned into the Indian Navy in August 2014. INS Kolkata is designed primarily as a high-end surface combatant, with long-range air-defence, anti-surface, and anti-submarine capabilities. The class is equipped to operate helicopters and carries the BrahMos supersonic cruise missile as its principal anti-surface strike weapon.

PNS Hunain (F-273) is an offshore patrol vessel. It was built by Damen Shipyards in Romania and commissioned in July 2024. It is the first of Pakistan’s larger OPV 2600-based follow-on vessels to the Yarmook-class patrol ships. Damen says the OPV 2600 design is intended for maritime security and military operations, including sustained operations in contested environments. It is approximately 98 metres long, has a displacement of about 2,600 tonnes, and is capable of speeds of up to about 24 knots. Its role includes maritime surveillance, patrol and security missions. Pakistan describes the vessel as a multi-purpose platform equipped with electronic-warfare, anti-ship and anti-air warfare capabilities, as well as self-protection and terminal defence systems. It can also embark a multirole helicopter.

What does India say happened?

According to the Indian account, INS Kolkata was conducting routine surveillance when PNS Hunain approached at high speed and manoeuvred dangerously close to the Indian ship. On September 18, a spokesperson of the Ministry of External Affairs said India had examined Pakistan’s response to the diplomatic protest and rejected its allegations. He said the Pakistani ship had conducted a “dangerous overtaking manoeuvre” that resulted in the collision.

India has maintained that the manoeuvre violated both the 1991 bilateral agreement and the International Regulations for Preventing Collisions at Sea. The Ministry said INS Kolkata suffered no major damage and remained deployed at sea.

Pakistan has given a different account, alleging that the Indian warship carried out a provocative manoeuvre during the encounter. The precise sequence of movements immediately before the collision therefore remains disputed.

What is Article 10 of the 1991 India-Pakistan agreement?

Article 10 of the Agreement between India and Pakistan on Advance Notice on Military Exercises, Manoeuvres and Troop Movements, signed on April 6, 1991, lays down a specific maritime safety provision. It states that naval ships and submarines of the two countries should not approach within three nautical miles of each other while operating in international waters, “so as to avoid any accident.” Three nautical miles is about 5.6 km.

The provision is part of a broader military confidence-building framework intended to reduce the risk of miscalculation between the two countries. It is a bilateral requirement, not a universal international maritime rule applicable to warships of all countries.

Has this happened before?

The September 2026 incident is the second reported India-Pakistan naval collision involving the 1991 framework. In June 2011, Pakistani warship PNS Babur came close to Indian Navy frigate INS Godavari during anti-piracy operations in the Gulf of Aden, causing minor damage. India lodged a protest, citing navigational-safety violations.

What happens next?

India has summoned Pakistan’s Chargé d’Affaires in New Delhi and lodged a strong protest. It has also instructed its Charge d’Affaires in Islamabad to raise the matter with Pakistan’s Foreign Ministry.

New Delhi has advised Pakistan to ensure that its military units exercise due care and comply with relevant bilateral agreements to prevent a recurrence. The fact that the collision occurred in international waters does not place the two navies outside agreed rules of conduct.

For now, the key unresolved question is the exact sequence of manoeuvres that brought the two vessels into close proximity.

The story so far:

On September 14, 2026, U.S. Air Force secretary Troy Meink said the country has “space control” weapons deployed in Earth’s orbit to defend U.S. forces against “hostile adversary action”. The disclosure drew backlash from Russia and China, among other quarters.

What is a ‘space control’ weapon?

As per the U.S. Space Force, ‘space control’ refers to military activities required to control the space domain. In 2025, the then-Space Force chief, Gen. Chance Saltzman, said such a device could possess both “kinetic and non-kinetic” capabilities and could disrupt or degrade an adversary’s capabilities.

‘Kinetic’ generally refers to physically damaging an object through impact, such as by smashing into it. Non-kinetic methods include electromagnetic interference that can jam or spoof a satellite’s communications, and directed energy systems that interfere with its sensors.

In fact, the current Space Force war-fighting framework recognises three kinds of counter-space operations: orbital, electromagnetic, and cyberspace.

What has the U.S. deployed?

We do not know. We also do not know how many units/instances of the system exist, what they are capable of, which orbits they are in, and whether they are kinetic or non-kinetic. Mr. Meink had said that while disclosing the weapon’s (or weapons’) existence would contribute to deterrence, revealing their operational details would subtract from the deterrence. There is also no indication whether these weapons are the same as the space-based interceptors the U.S. government has planned for the ‘Golden Dome’ missile defence programme. These interceptors are still undergoing tests.

What will the weapons defend against?

Mr. Meink has referred to “hostile adversary action”. Incumbent Space Force chief Gen. Douglas Schiess has also referred to “space-enabled attacks”.

In other instances over the years, U.S. officials have repeatedly singled out Russian and Chinese counter-space capabilities as reasons for their government to develop similar capabilities of its own, to protect its own satellites. Russia and China have also demonstrated sophisticated satellite manoeuvres in orbit.

For example, in 2020, two Russian satellites manoeuvred close to a U.S. government satellite, prompting the Space Command to call the behaviour potentially threatening. In 2022, the Chinese Shijian-21 satellite used a robotic arm to tow a defunct Chinese geostationary satellite into a graveyard orbit.

However, we do not know the circumstances in which the U.S. will use its weapons as the government has not published the rules of engagement for orbital weapons.

Is it legal to have weapons in orbit?

The relevant instrument is the Outer Space Treaty, which entered into force in 1967, during the Cold War and the nuclear arms race between the U.S. and the Soviet Union. It prohibits its party states, which include the U.S., Russia, and China today, from placing nuclear weapons or other weapons of mass destruction in orbit or stationing them elsewhere in outer space. It also obviates states from setting up military bases and conducting weapons tests on the moon and other celestial bodies.

However, the treaty does not prohibit states from placing conventional weapons in orbit. The treaty also says all activities in outer space must comply with international law, which means other bodies of international law governing the use of force and armed conflicts can be applied to military operations in orbit. As the U.S. government has not disclosed what its orbital weapons are capable of, it is not possible to say whether it violates specific treaty conditions.

Can other countries prevent unilateral action?

There is no international body to order the U.S. to remove its weapons from orbit. However, there are various diplomatic and legal avenues through which other countries can seek more information and negotiate restraints. For example, Article IX of the treaty requires states to have “due regard” for the interests of other parties, which a (party) state can invoke if it believes U.S. activities in orbit could harm its own peaceful use of space. States can also endeavour to draft new orbital governance rules through the United Nations process on the Prevention of an Arms Race in Outer Space, whose third substantive session is scheduled for November. Countries can also raise the issue before the UN Security Council or the General Assembly as a threat to international peace and security, under Article 35 of the UN Charter.

The story so far: On September 11, Union Transport Minister Nitin Gadkari said the Automotive Research Association of India (ARAI) was exploring the possibility of blending isobutanol with diesel. Isobutanol is an alcoholic compound with inflammable properties and is used as a solvent in several industries, including painting. Mr. Gadkari said ARAI was studying the possibility of blending isobutanol with diesel, after efforts to blend ethanol with diesel was unsuccessful.

Also Read | What has been the impact of ethanol blending?

Is isobutanol better suited for diesel?

The discussion on the potential use of isobutanol primarily stems from the assumption that the alcoholic compound blends better with diesel, and after the blending experiment with diesel and ethanol failed. Ethanol, however, is available in surplus; as a biofuel, it is being seen as an important contributor to the government’s objective of scaling the net-zero emission target by 2070. At the annual conclave of the India Sugar and Bio-Energy Manufacturers Association (ISMA), Reji Mathai, director of ARAI, explained how isobutanol blended better with diesel compared with ethanol. “There was no need to add any complement [for efficiency], and isobutanol’s properties are better than ethanol for blending diesel. This is one [area] where studies are to be taken up,” he said.

More importantly, as Mr. Mathai pointed out, the flash point, or the lowest temperature at which isobutanol yields a vapour igniting a momentary flash, is higher than ethanol. A lower flash point was among the reasons that ethanol was not considered ideal for blending with diesel. Fuels with lower flash points are more volatile and entail a higher risk of catching fire. The other aspect relates to diverting some of the raw material required to produce ethanol to make isobutanol, as there is already a surplus of ethanol. According to an ISMA note, even after catering for industrial use in different States, the potential for ethanol supply is “more than 50% of the requirement” for the one-fifth blending with petrol. In addition to this, the sugar manufacturers’ association has also urged the government to revise the procurement prices for ethanol produced from cane juice/syrup or B-heavy molasses. The prices have not been changed since Ethanol Supply Year (ESY) 2022-23, while the Fair and Remunerative prices (FRP), or the minimum price sugar mills are required to pay farmers for sugarcane has increased by 16.5% during the period. “This imbalance has eroded economic viability, discouraged ethanol production and risked a build-up of surplus sugar in the domestic market,” it stated. Thus, the proposed blending also opens another avenue for the surplus production to be used.

How economical is it to make isobutanol?

Isobutanol can be produced from the same feedstock required to produce ethanol, such as sugarcane syrup and molasses and grains, among others. ISMA’s Director General Deepak Ballani explained the process to The Hindu, “Natural sugars are fermented by specially designed microbes under sterile conditions, unlike conventional yeast that produces ethanol; these engineered microbes are tuned to produce isobutanol.” On the aspect of costs, Mr. Ballani, taking the example of a sugar refinery, pointed out that producing isobutanol from biomass would require retrofitting a fermentation tank, and a distillation tank to separate ethanol from isobutanol. “A plant with a production capacity of 150 kilo litres per day (klp/d) can easily produce 125 klp/d of ethanol and 20 klp/d of isobutanol without a lot of changes to the overall infrastructure,” he stated.

What are some of the issues to consider?

Mathew Abraham, an automobile consultant and researcher who has previously worked with blending fuel types, noted two potential concerns emanating from isobutanol’s significantly lower cetane number compared with diesel, and about flash points. At the foremost, according to Mr. Abraham, isobutanol and diesel may have issues on miscibility (ability of two substances to mix to form a homogenous mixture) though it can be sorted out by mixing biodiesel to the blend. The latter refers to the fuel manufactured from non-edible vegetable oils, used cooking oil and/or animal fat.

Further, another point to note is the impact of the blend on the cetane number, which is a measure of combustion quality. An ideal combustion translates to rapid ignition and the fuel combusting completely to produce the necessary energy. Mr. Abraham notes the alcoholic compound’s significantly lower cetane number compared with the base fuel, diesel, would reduce the blend’s overall cetane number.

Also, a lower cetane number raises concerns about ‘[diesel] knock’ which can result in reduced power and can potentially damage engines. ‘Knocking’ occurs when the fuel burns unevenly and/or prematurely in the vehicle’s fuel cylinder, also generating an audible sound. However, Mr. Abraham added that the cetane value can be restored through proper additives which would entail incremental costs.

Mr. Abraham further stated that the proposed blend would have an impact on reducing emission and help with import substitution, but the riders must be addressed, and proper studies should be initiated encompassing varied vehicle classes and types. More importantly, he emphasised, “No more than 10% blending [of isobutanol] should be considered, else it could have an impact on engines.”

The blending paradigm is still being studied and the pilot project would take about 18 months to complete, according to Mr. Mathai. If successful, India would be the first country to have blended isobutanol with diesel.