New Delhi, April 6 -- A seemingly harmless mistake by Donald Trump's national security advisor Mike Waltz and his iPhone could have been the real reason why a journalist was added to a signal chat that disclosed US plans to strike Yemen.

According to a report by The Guardian quoting three sources, Waltz mistakenly saved the number of The Atlantic Magazine editor Jeffrey Goldberg under someone else's name. The official had originally intended to add this person to the group chat named 'Houthi PC small group', the report revealed.

An internal investigation by the White House highlighted this as one of the several missteps that went unnoticed until Waltz made the group in March.

Donald Trump initially intended to fire Waltz, more due to t...