India conducted military strikes against Pakistan overnight, hitting numerous sites in Pakistan-controlled Kashmir and deeper into Pakistan itself. Security officials say precision strike weapon systems, including drones, were used to carry out the strikes.

While there's still much uncertainty around what's happened, it is clear both sides are closer to a major conflict than they have been in years – perhaps decades.

We've seen these kinds of crises before. India and Pakistan have fought full-scale wars many times over the years, in 1947, 1965, 1971 and 1999. There were also cross-border strikes between the two sides in 2016 and 2019 that did not lead to a larger war.

These conflicts were limited because there was an understanding, given both sides possess nuclear weapons, that escalating to a full-scale war would be very dangerous. That imposed some control on both sides, or at least some caution.

There was also external pressure from the United States and others on both occasions not to allow those conflicts to spiral out of control. While it's possible both sides will exercise similar restraint now, there may be less pressure from other countries to compel them to do so.

In this context, tensions can escalate quickly. And when they do, it's difficult to get both sides to back down and return to where they were before.

Why did India strike now?

India says it was retaliating for a terror attack last month on mostly Indian tourists in heavily militarised Kashmir, which both sides claim. The attack left 26 dead.

There was a claim of responsibility after the attack from a group called the Resistance Front, but it was subsequently withdrawn, so there's some uncertainty about that. Indian sources suggest this group, which is relatively new, is an extension of a pre-existing militant group, Lashkar-e-Taiba, which has been based in Pakistan for many years.

Pakistan has denied any involvement in the tourist attack. However, there has been good evidence in the past suggesting that even if the Pakistani government hasn't officially sanctioned these groups operating on its territory, there are parts of the Pakistani establishment or military that do support them. This could be ideologically, financially, or through other types of assistance.

In previous terror attacks in India, weapons and other equipment have been sourced from Pakistan. In the Mumbai terror attack in 2008, for instance, the Indian government produced evidence it claimed showed the gunmen were being directed by handlers in Pakistan by phone.