WASHINGTON, July 21 (Reuters) - Three Republican House

lawmakers on Monday asked the CEOs of Alphabet,

Facebook-parent Meta, Amazon.com ( AMZN ) and Microsoft ( MSFT )

if the tech firms have adopted adequate safeguards to

address growing concerns about China and Russia on submarine

communications cables.

Washington has been raising alarm about the network of more

than 400 subsea cables that handle 99% of international internet

traffic. The letter signed by Representative John Moolenaar, who

chairs a House panel on China and two other Republicans, raised

concerns that entities affiliated with China "such as SBSS,

Huawei Marine, China Telecom, and China Unicom, have continued

to provide maintenance or servicing to cable systems in which

your companies maintain direct or indirect operational

involvement or ownership."