Philip H. Gordon: “NATO remains committed to the article 5 principle of collective defense.”

These are very serious charges. We have looked at them carefully and came to the view that they deserved, indeed required, serious investigation.

I don't think that's a habit the United States should want to develop.

NATO is vital to U.S. security.

Absolutely. As I said, these are very serious charges. We have looked at them carefully and came to the view that they deserved, indeed required, serious investigation.