He used part of his speech, much of which he gave speaking in Chinese, to convey to Chinese leaders America's serious concern with China's invasion of Vietnam a week earlier. Henry Kissinger described the multipronged invasion which may have included up to 400,000 Chinese soldiers. Blumenthal asked them to withdraw their troops "as quickly as possible," since it carried the "risk of wider wars." The Chinese were particularly impressed by Blumenthal's speech, adds Katz. And although the effect of his speech is not known, the Chinese army did withdraw a few weeks after his visit.