Article 4 and Article 5 are the two clauses of the North Atlantic Treaty that get quoted every time a Russian drone crosses a border or a missile lands near allied territory. They do very different things. Article 4 is a right to call a meeting. Article 5 is the mutual defence pledge, the promise that an armed attack on one ally counts as an attack on all. Article 4 has been used nine times since 2003.

For years US export controls stopped American chips and tools from reaching Chinese military-linked users, while American venture capital could still fund the Chinese startups building rival chips and AI models. The outbound investment rules close that gap. Since January 2, 2025, US persons have been barred from some investments in Chinese semiconductor, quantum and AI companies, and must report others to the Treasury Department. This is a different tool from export controls.

A passkey is a login credential made of a cryptographic key pair instead of a shared secret. You unlock it with whatever unlocks your phone or laptop (a fingerprint, your face, a PIN), and the website never receives anything it could leak or that you could be tricked into typing somewhere else. Passkeys are the consumer name for FIDO2 credentials, and Apple, Google and Microsoft have supported them since 2022. They fix the two biggest problems with passwords, phishing and reuse, almost completely.

Post-quantum cryptography (PQC) is the set of public-key algorithms built to survive an attack by a large quantum computer. It runs on ordinary computers and ordinary chips. Nothing about it is quantum except the threat it is designed against. The reason anyone outside a cryptography department should care is simple: almost every secure connection you make today, from a bank login to a software update, depends on RSA or elliptic-curve cryptography (ECC), and both fall apart once a big enough quantum machine exists.

A neodymium-iron-boron (NdFeB) magnet is the strongest permanent magnet you can buy at scale. It sits inside most electric vehicle motors, many wind turbines, missile guidance fins, drones, hard drives and phone speakers. Getting one made takes four separate industrial steps: mining the ore, separating it into individual rare earth oxides, turning those oxides into metal and alloy, then pressing and sintering the alloy into a finished magnet. China leads every one of those steps, and its lead gets bigger the further down the chain you go.

Sanctions are legal restrictions that stop people and companies from dealing with a named target: a government, a company, a ship, an individual. Four systems matter most for anyone doing business across borders. The United States runs the most powerful one, because so much of the world’s money moves in dollars. The EU and the UK run their own regimes, which overlap with Washington’s but are written and enforced differently. The UN Security Council sits above all three in law but has no enforcement arm of its own.

Short interest is the number of a company’s shares that have been sold short and not yet bought back. A short seller borrows shares, sells them, and hopes to buy them back later at a lower price before returning them to the lender. Until that buyback happens, the position is open, and it shows up in the short interest count. Investors watch the figure for two reasons. It tells you how many professional skeptics are betting against a stock.

This page covers six small open infrastructure projects that each do one job: an embedded database for connected devices, a reverse proxy, browser tools for key-value stores, a policy language that keeps answers ready as data arrives, a setup compiler for AI coding agents’ machines, and a network sandbox for agents. They’re separate projects, each with its own site and repository. What they share is an old habit. SQLite showed that a database can be one file linked into a program; nginx showed that a web server can be small and fast.

Circuit breakers are the rules that stop trading when prices move too far, too fast. US stock markets have two main layers. Market-wide circuit breakers halt every stock and options exchange when the S&P 500 falls 7%, 13% or 20% in a day. Limit Up-Limit Down (LULD) bands work one stock at a time, pausing trading for five minutes when a single name breaks out of its allowed price range. On top of those sit ordinary trading halts that exchanges call for news, plus a short-sale restriction that kicks in after a 10% drop.

Every WiFi device you own speaks some version of IEEE 802.11, the wireless LAN standard first published in 1997 and amended dozens of times since. The IEEE writes the engineering; the Wi-Fi Alliance, an industry group formed in 1999, certifies products and owns the brand names on the box. That split is why one technology has two sets of names (802.11ax and “Wi-Fi 6” are the same thing) and why the dates you find online rarely agree: certification often starts years before the IEEE formally approves a standard.