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.

UAPs display unpredictable behavior, combining structured and erratic actions. This unpredictability hinders understanding their purpose or origin.

Some UAPs seem to react to human activities like aircraft proximity or electronic countermeasures, though this isn't consistently observed.

There's some indication of UAP activities being influenced by specific times or locations, but the data is too inconclusive for definitive patterns.

Aggressive UAP behavior is rare, with most incidents being non-aggressive and observational.

Frequent UAP behaviors include erratic movements, formation flying, and hovering.

These reports come from varied sources, including credible ones like pilots and military personnel, but they are still subject to ongoing examination.

Limited data exists on weather influencing UAP behavior, although some interactions with weather systems have been noted.

Currently, there are no universally acknowledged countermeasures for all UAP behavior patterns, and research into effective strategies continues.

UAPs in controlled airspace pose a significant safety concern for aviation, even though direct impacts are infrequent.

While certain UAP behaviors mimic natural occurrences like ball lightning, many display characteristics unexplained by current scientific knowledge.

While a UAP's shape might hint at its aerodynamics or functionality, it doesn't conclusively reveal its origin or purpose. Various shapes have been noted in different contexts, adding complexity to this aspect.

Estimations of UAP size are often inconsistent, influenced by factors like observation distance and visual barriers. Corroborating witness accounts with radar or other detection methods is beneficial.

A UAP's luminosity may provide clues about its energy source, camouflage ability, or intent. However, the diversity in colors and brightness levels complicates drawing definite conclusions.

Sound reports from UAPs vary significantly, from complete silence to mechanical noises, possibly indicating propulsion methods or communication forms.

Visible technology on UAPs, like propulsion systems, can suggest a level of technological advancement. Invisible technology, however, doesn't necessarily imply lower capability but may point to more advanced or hidden systems.

Environmental interactions of UAPs are crucial for understanding their capabilities and potential objectives. These interactions should be closely studied for any patterns or consistencies.

Common environmental interactions include leaving trails or affecting electronics, but there is significant variability. Ongoing research is focused on identifying any consistent themes or characteristics.