View source for DESOTO patrol

'''DESOTO patrols''' ('''De'''Haven '''S'''pecial '''O'''perations off '''T'''singta'''O''')<ref name="Montgomery">{{cite web 
  | last = James W. Montgomery
  | title = The First DESOTO Patrol
  | url = http://ussdehaven.org/first_desoto_patrol.htm
  | accessdate =  2010-05-04}}</ref>
were patrols conducted by [[United States Navy|U.S. Navy]] [[destroyer]]s equipped with a mobile "van" of [[signals-intelligence]] equipment used for intelligence collection in hostile waters.<ref name=NSAtonkin>{{cite web
 |last         = National Security Agency
 |authorlink   = National Security Agency
 |title        = Gulf of Tonkin
 |work         = declassified materials, 2005 and 2006
 |date         = 30 November 2005
 |url          = http://www.espionageinfo.com/An-Ba/Army-Security-Agency.html
 |accessdate   = 2007-10-02
 |archive-url  = https://web.archive.org/web/20070911222802/http://www.espionageinfo.com/An-Ba/Army-Security-Agency.html
 |archive-date = 2007-09-11
 |url-status     = dead
}}</ref>
The {{USS|De Haven|DD-727|6}} became the namesake for these patrols.<ref name="cryptolog-got">{{cite web|url= http://www.nsa.gov/public_info/_files/gulf_of_tonkin/articles/rel1_gulf_tonkin_incident.pdf|title= The Gulf of Tonkin Incident|accessdate= 6 Jul 2013|date= Feb 1975|archive-url= https://web.archive.org/web/20130918030716/http://www.nsa.gov/public_info/_files/gulf_of_tonkin/articles/rel1_gulf_tonkin_incident.pdf|archive-date= 2013-09-18|url-status= dead}}</ref> ''De Haven'' performed the first patrol off the coast of [[China]] in April 1962. The {{USS|Agerholm|DD-826|6}} carried out the first patrol to target North Vietnam in the Gulf of Tonkin in December 1962.<ref name="cryptolog-got"/>
[[File:USS De Haven (DD-727).jpg|thumb|USS ''De Haven'']]
These patrols were initially a response to the Chinese Communists' unexpected re-definition{{when|date=July 2019}} of their territorial waters to include all waters shoreward from lines drawn tangentially to, and between, twelve-mile circles drawn around their offshore islands. Such a declaration represented a huge expansion of their claims. This inhibited the lawful navigation of international waters as defined by US interests and increased the likelihood and frequency of formal diplomatic "serious warnings" issued by [[Beijing]] when any Seventh Fleet units navigated through these areas. This became a situation to which Commander Seventh Fleet felt compelled to respond.<ref name="Montgomery"/>

These types of patrols had previously been conducted off the coasts of the [[Soviet Union]], [[China]], and [[North Korea]], but are perhaps of greatest significance for their role in the [[Vietnam War]].<ref name="Montgomery"/> There were three components to the purpose of these patrols. First, they would establish and maintain the presence of the
[[U.S. Seventh Fleet]] in the international waters off the China coast and later the Vietnamese coast. Second, they would serve as a minor Cold War irritant to the Chinese Communists. Third, they would collect as much intelligence
as possible during the patrols.<ref name="cryptolog-got"/>

Tactically, the patrols off [[Vietnam]] aimed to intercept [[North Vietnamese Army]] intelligence and to relay it to [[South Vietnamese Army]] forces. With the intercepted communications, the [[South Vietnamese]] were able to more effectively coordinate their raids. The [[aircraft carrier]] {{USS|Ticonderoga|CV-14|6}} provided destroyers taking part in the DESOTO patrols off Vietnam with [[air support]].<ref name="Montgomery"/>

The DESOTO patrols off Vietnam from 1963 onwards formed part of a larger scheme known as [[Operation 34A]]. Run by the Department of Defense at the time, Operation 34A, or "OPLAN 34Alpha" was a [[Classified information#Top_Secret_(TS)|top-secret]] program consisting primarily of [[covert]] actions against the North Vietnamese.{{citation needed|date= February 2017}}

==Patrols and SIGADs==
The naval Direct Support Units (DSUs) based out of the [[Naval Station San Miguel|U.S. Naval Communication Station, Philippines]], in San Miguel, [[Philippines]] ([[SIGAD]] USN-27)<ref name="nsa_sigint2">{{cite web|url=http://www.nsa.gov/public_info/_files/cryptologic_histories/spartans_in_darkness.pdf|title=Spartans in Darkness:American SIGINT and the Indochina war, 1945-1975|pages=498–500|date=24 February 1998|accessdate=11 June 2013|archive-url=https://web.archive.org/web/20130918015958/http://www.nsa.gov/public_info/_files/cryptologic_histories/spartans_in_darkness.pdf|archive-date=2013-09-18|url-status=dead}}</ref> used the SIGAD USN-467 as a generic designator for their missions. Each specific patrol received a letter suffix for its duration. The subsequent mission would receive the next letter in an alphabetic sequence.<ref name="nsa_shadow">{{cite book|author=William Gerhard|title=In the Shadow of War (To the Gulf of Tonkin), Cryptologic History Series, Southeast Asia| date=June 1969| publisher=National Security Agency|page=51}}</ref>

===Declassified SIGADs===
The following table lists the patrols that have been declassified.<ref name="cryptolog-got"/><ref name="memoP12">{{cite web|url=http://www.nsa.gov/public_info/_files/gulf_of_tonkin/memos/rel1_latimer.pdf|title=Operational History|page=12|date=26 May 1965|accessdate=6 July 2013|archive-url=https://web.archive.org/web/20130918030613/http://www.nsa.gov/public_info/_files/gulf_of_tonkin/memos/rel1_latimer.pdf|archive-date=18 September 2013|url-status=dead}}</ref><ref name="memoP2">{{cite web|url=http://www.nsa.gov/public_info/_files/gulf_of_tonkin/memos/rel1_latimer.pdf|title=Operational History|page=2|date=26 May 1965|accessdate=6 July 2013|archive-url=https://web.archive.org/web/20130918030613/http://www.nsa.gov/public_info/_files/gulf_of_tonkin/memos/rel1_latimer.pdf|archive-date=18 September 2013|url-status=dead}}</ref>
[[File:DESOTO patrol mission map off Vietnam 1964.png|thumb|DESOTO patrol mission map off Vietnam.]]
{| class="wikitable" style="margin: 1em auto 0em auto; text-align:center"
|-
!  Patrol Number
!  Patrol Dates
!  Primary Patrol Ship
!  SIGAD
|-
| 1
| 14–20 April 1962
| {{USS|De Haven|DD-727|6}}
| USN-467?
|-
| 9
| December 1964
| {{USS|Agerholm|DD-826|6}}
| USN-467?
|-
| ?
|  25 February - 12 March 1964
| {{USS|John R. Craig|DD-885|6}}
|  USN-467Y
|-
| 18
| 28 July - 23 August 1964
| {{USS|Maddox|DD-731|6}}
| USN-467N
|-
| 19
| 14–21 September 1964
| {{USS|Morton|DD-948|6}} 
| USN-467P
|-
| 20
| 1–15 October 1964
| {{USS|Richard S. Edwards|DD-950|6}}
| USN-467R-1
|-
| 21
| 15 October - 14 November 1964
| USS ''Morton''
| USN-467R-2
|-
| 22
| 8–14 November 1964
| USS ''Richard S. Edwards''
| USN-467S
|-
| 23
| 14 November - 27 December 1964
| USS ''Richard S. Edwards''
| USN-467R-3
|-
| 24
| 8–14 February 1965
| {{USS|Towers|DDG-9|6}}
| USN-467D
|-
| 25
| 15 February - 19 March 1965
| {{USS|Buchanan|DDG-14|6}}
| USN-467D
|-
| 26
| 19 March - 21 April 1965
| USN-27/USS ''Buchanan''
| USN-467D
|-
|}

==Gulf of Tonkin Incident==
[[File:USS Maddox (DD-731) underway at sea, circa the early 1960s (NH 97900).jpg|thumb|USS ''Maddox'']]
SIGAD USN-467N specifically designates the DSU aboard {{USS|Maddox|DD-731|6}} during the patrol involved with the [[Gulf of Tonkin incident]].<ref name="nsa_shadow"/><ref name="nsa_skunk">{{cite web|url=http://www.nsa.gov/public_info/_files/cryptologic_quarterly/Skunks.pdf |title=Skunks, Bogies, Silent Hounds, and the Flying Fish: The Gulf of Tonkin Mystery, 2-4 August 1964 |page=50 |date= 24 February 1996 |accessdate= 11 June 2013 |url-status=dead |archiveurl=https://web.archive.org/web/20131011150926/http://www.nsa.gov/public_info/_files/cryptologic_quarterly/Skunks.pdf |archivedate=October 11, 2013 }}</ref> This patrol was 18th DESOTO type patrol (each with a [[Naval Security Group]] detachment embarked) conducted since 1962.<ref name="memoP10">{{cite web|url=http://www.nsa.gov/public_info/_files/gulf_of_tonkin/memos/rel1_latimer.pdf|title=Operational History|page=10|date=26 May 1965|accessdate=6 July 2013|archive-url=https://web.archive.org/web/20130918030613/http://www.nsa.gov/public_info/_files/gulf_of_tonkin/memos/rel1_latimer.pdf|archive-date=18 September 2013|url-status=dead}}</ref> On August 2, 1964, the destroyer ''Maddox'', engaged three North Vietnamese Navy torpedo boats of the 135th Torpedo Squadron.<ref name="Moise, p. 78">{{Harvnb|Moïse|1996|p=78}}.</ref> A [[sea battle]] resulted, in which ''Maddox'' expended over two hundred and eighty {{convert|3|in|mm|adj=on|0}} and {{convert|5|in|mm|adj=on|0}} shells, and in which four USN [[F-8 Crusader]] jet fighter bombers strafed the torpedo boats. One US aircraft was damaged, one {{convert|14.5|mm|adj=on|sp=us}} round hit the destroyer, three [[P 4-class torpedo boat|North Vietnamese torpedo boat]]s were damaged, and four North Vietnamese sailors were killed and six were wounded; there were no U.S. casualties.<ref>{{Harvnb|Moïse|1996|pp=78, 82, 92}}.</ref>

==Post Gulf of Tonkin Engagement==
[[File:USS Morton (DD-948) off Aruba in October 1959.jpg|thumb|USS ''Morton'']]
Even after the Gulf of Tonkin incident, the DESOTO patrols continued. On 11 September 1964 the Director of the Naval Security Group, Pacific (DIRNAVSECGRUPAC) informed the Director of the NSA (DIRNSA) of plans for an intercept team, SIGAD USN-467P, to be aboard {{USS|Morton|DD-948|6}}. The patrol was conducted by USS ''Morton'' and {{USS|Richard S. Edwards|DD-950|6}} approximately one month after the Gulf of Tonkin incident.<ref name="desotorev">{{cite web|page=5|url=http://www.nsa.gov/public_info/_files/gulf_of_tonkin/chrono/rel2_lang.pdf|title=REVIEW OF THE DESOTO PATROL: 16-20 September 1964|accessdate=6 Jul 2013|date=14 Jan 1965|archive-url=https://web.archive.org/web/20130918030603/http://www.nsa.gov/public_info/_files/gulf_of_tonkin/chrono/rel2_lang.pdf|archive-date=2013-09-18|url-status=dead}}</ref> During this patrol ''Morton'' fired upon five fast closing targets, but was unable to confirm the targets visually.<ref name="desotorev"/> Based on radar surveillance the patrol claimed hits on three of the targets.<ref name="desotorev"/>

==See also==
* [[Gulf of Tonkin Incident]]
* [[National Security Agency]]
* [[Naval Security Group]]
* [[Signals Intelligence]]
* [[USS Liberty incident|USS ''Liberty'' Incident]]
* [[USS Pueblo Incident|USS ''Pueblo'' Incident]]

==References==
{{reflist|30em}}

===Works cited===
* {{cite book |last1=Moïse |first1=Edwin E. |title=Tonkin Gulf and the escalation of the Vietnam War |date=1996 |publisher=University of North Carolina Press |location=Chapel Hill |isbn=0-8078-2300-7}}

{{DEFAULTSORT:Desoto Patrol}}
[[Category:Destroyers of the United States Navy]]