Ha-HA-HA There are no safeguards.
But the amount of Securities held by China is considered to minimal and would have little impact to economy.
From Wikipedia
“The National Defense Authorization Act of the fiscal year 2012 included a provision requiring the Secretary of Defense to conduct a “national security risk assessment of U.S. federal debt held by China.”
“The Department issued its report in July 2012, stating that ‘attempting to use U.S. Treasury securities as a coercive tool would have limited effect and likely would do more harm to China than to the United States. As the threat is not credible and the effect would be limited even if carried out, it does not offer China deterrence options, whether in the diplomatic, military, or economic realms, and this would remain true both in peacetime and in scenarios of crisis or war.’ ”
“A significant number of economists and analysts dismiss any and all concerns over foreign holdings of United States government debt denominated in U.S. dollars, including China’s holdings.”