During this period, he also attended the Staff College Course (1993-1994), the Command and Staff College Course (1996-1997) at the Army War School in Civitavecchia as well as the Joint Command and Staff College Course (1997) at the Joint Command and Staff College in Rome.
From August 1997 to July 1998, after attending a special course organized by the Free International University for Social Studies (LUISS), he served as Tutor and Professor of "Method for solving operational problems" at the Joint Command and Staff College.
As a General Staff Officer, he served in the Public Information Agency of the Italian Army as Deputy Director (1998-1999). He held the position of Head of the Public Information Office at the Army General Staff (2000-2004). He became Head of the Office of the Assistant Chief of the General Staff (2006-2008).
As a Senior Officer, he commanded the Squadron Group of the “Savoia Cavalleria (3°)” Regiment (1999-2000) and the “Lancieri di Montebello (8°)” Regiment (2005-2006). As a General Officer, he commanded the “Pozzuolo del Friuli” Cavalry Brigade (2010-2011) of which he was previously Deputy Commander from January 2009 to June 2010. He also commanded the Italian Joint Force Headquarters (2011-2012). 
From September 2013 to August 2015, he was Director of the General and Financial Planning Department at the Army General Staff. Previously, he had been Deputy Director of the General Planning Department (August 2012 - September 2013).
From August 2015 to September 2016, he was appointed Commander of the NATO “KFOR” mission in Kosovo.
From November 2016 to February 2019, he was Head of the General Planning and Defence Budget Planning Department at the Defence General Staff.
In February 2019, he was appointed Deputy Commander of the Operational Land Forces Command and Army Operational Command.

He participated in the following out-of-area operations: “Pellicano” Operation in Albania, as Officer in charge of the operations at the Italian Contingent Headquarters (Sept. 1991 - Feb. 1992); “Joint Guardian” Operation in Kosovo, as Commander of the Squadron Group of the “Sauro” Task Force (Jun. - Sept. 2000); "Leonte" Operation in Lebanon, as the 9th  Commander of the Joint Task Force Lebanon and of Sector West of UNIFIL (Nov. 2010 - May 2011); “KFOR” Operation in Kosovo, as 20th  Commander of the mission (Aug. 2015 - Sept. 2016).
He attended the US Army War College in Pennsylvania (Jun. 2004 – Jun. 2005) and the Royal College of Defence Studies in Great Britain (Jan. – Dec. 2008).
He assumed command of the NATO Rapid Deployable Corps – Italy on 9 December 2019. 

He is a journalist. He graduated in “Strategic Sciences” at the University of Turin and in “International and Diplomatic Sciences” at the University of Trieste. He obtained the second level Master in “Strategic Sciences” at the University of Turin, the Master in “Strategic Studies” at the War College of the U.S. Army. He attended the Postgraduate Course in “Public and Institutional Communication and Public Information” at the Roma Tre University, the Post Conflict Rebuilding Management Senior Course at the Italian Army Post Conflict Operations Study Centre in Turin as well as several highly specialized courses as Press Officer.

Lieutenant General Guglielmo Luigi MIGLIETTA is passionate about horse riding and plays golf.
Since 1992 he has been married to Mrs. Laura RASSA.