Why does Vanguard require their clients to hold international stocks and bonds if they are enrolled in their personal advisory services? Or they will unenroll the client. Are they dictating how the clients must invest?

Holding 20% of your bond exposure in international bonds is the least amount of international bond exposure we can allow an investor to hold in an advised portfolio. In other words, we feel so strongly the merits of having at least a minimal amount of international stock and bond exposure, that if an investor simply is unwilling to hold any international stock and bond exposure at all, then they cannot be enrolled in Personal Advisor Services.