While Britain and America were engrossed in the pageantry and diplomacy of a US presidential visit last week, another event pretty much went unnoticed in most Western capitals - and it could have a profound impact on geopolitics.
The "Strategic Mutual Defence Agreement" was signed by Saudi Crown Prince Mohammed bin Salman and Pakistan Prime Minister Shehbaz Sharif on 17 September.
Seen as an "Islamic NATO" in the making, at its core is the clause that "any aggression against either country, shall be considered an aggression against both".
Article 5 of NATO states the same, and is the cornerstone principle of collective defence that binds members of the alliance.
If an ally is attacked, each member will consider it an attack against them all and will take action to help. This clause has often been cited since Putin's war on Ukraine.
Pakistan and Saudi Arabia have a longstanding relationship, with Pakistan willing to defend the holy sites of Mecca and Medina as Shia Iran threatened the Kingdom.
The new pact between Sunni Saudi Arabia, a country considered the heart of the Islamic world, with Pakistan - the only Muslim nuclear nation - is bound to set a new order.
Pakistani defence minister Khawaja Asif said "the deterrence that we get from nuclear weapons, and what we have, and the capabilities we possess, will be made available to Saudi Arabia according to this agreement".
