No, they're reported worldwide. The United States' sophisticated global sensors might explain its higher detection rates. Key UAP disclosures, such as the UAP Disclosure Act of 2023, also focus attention on the U.S. However, countries like France, Portugal, Belgium, Peru, and Iran have their own UAP experiences.

The exact reasons for these supposed crashes are not established, lacking a unified theory or solid evidence. It's crucial to first verify these crashes before exploring their causes. Current knowledge about NHI crafts' crash resistance is limited.

The intent behind NHI activities remains unclear, with no concrete evidence to support any specific theory.

The timeline of NHI-human interaction is uncertain. Some sources, like David Grusch, imply US involvement with UAPs dates back to the 1930s or 40s. If verified, this suggests NHI presence on Earth since the mid-20th century.

The characteristics and appearance of NHIs are yet to be clearly defined. The UAP Disclosure Act of 2023 provides some basic descriptions, but they don't offer a comprehensive understanding.