The White House political pull that won the embassy in New Delhi for career diplomat John Gunther Dean was exerted last year to keep him on as ambassador to Thailand over the objections of the State Department hierarchy, according to officials familiar with the controversial situation.

Dean has served overseas continuously for 20 years without an assignment in Foggy Bottom, which is highly unusual and an exception to normal Foreign Service guidelines. When he approached the end of a three-year term as ambassador to Thailand last year, Dean was told by ranking State Department officials that he should return to a post in Washington. This was countermanded through the intervention of White House deputy chief of staff Michael K. Deaver, according to informed sources, resulting in a fourth year for Dean in the Bangkok post.

Deaver's intervention on behalf of Dean has set off a furor among some career Foreign Service officers, who say they reasonably expect some pressure on behalf of political appointees but are dismayed when it is applied on behalf of one of their own.

The plan to bring Dean home this year also ran afoul of Deaver's special interest in the career envoy. At Deaver's insistence, Dean is expected to be named ambassador to India, a particularly important post since Rajiv Gandhi assumed power. Since 1965, Dean has served successively in Paris, Vietnam, Laos, Cambodia, Denmark, Lebanon and Thailand, with a stint in 1969-70 at Harvard University.