following schooling at wellington college and the royal military college, sandhurst, strettell was commissioned as a second lieutenant on the unattached list on 20 january 1900 "with a view to [his] appointment on the indian staff corps". on 22 april 1901, he entered the indian staff corps with the same rank, before being transferred to the indian army and promoted to lieutenant the following may. he served with the 13th rajputs in 1901 and the 3rd punjab cavalry in 1902 during the waziristan campaign of 1901–02. promotion to the rank of captain on 20 january 1909 was followed by service in the burma military police, during which time he took part in the nmai-hka expedition between 1912 and 1913.