Asymmetric warfare
The NATO bombing of Yugoslavia (1999), which pitted NATO air power against the Yugoslav armed forces during the Kosovo war, can also be classified as asymmetric, exemplifying international conflict with asymmetry in weapons and strategy/tactics.

21st century: 

Israel/Palestine: The ongoing conflict between Israel and some Palestinian organizations (such as Hamas and PIJ) is a classic case of asymmetric warfare. Israel has a powerful army, air force and navy, while the Palestinian organizations have no access to large-scale military equipment with which to conduct operations; instead, they utilize asymmetric tactics, such as paragliding, small gunfights, cross-border sniping, airstrikes, and others.

Sri Lanka: The Sri Lankan Civil War, which raged on and off from 1983 to 2009, between the Sri Lankan government and the Liberation Tigers of Tamil Eelam (LTTE) saw large-scale asymmetric warfare. The war started as an insurgency and progressed to a large-scale conflict with the mixture of guerrilla and conventional warfare, seeing the LTTE use suicide bombing (male/female suicide bombers) both on and off the battlefield use of explosive-filled boats for suicide attacks on military shipping; and use of light aircraft targeting military installations.

Iraq: The victory by the US-led coalition forces in the 1991 Persian Gulf War and the 2003 invasion of Iraq demonstrated that training, tactics and technology could provide overwhelming victories in the field of battle during modern conventional warfare. After Saddam Hussein's regime was removed from power, the Iraq campaign moved into a different type of asymmetric warfare where the coalition's use of superior conventional warfare training, tactics and technology was of much less use against continued opposition from the various partisan groups operating inside Iraq.

Syria: Much of the 2012–present Syrian Civil War has been asymmetrical. The Syrian National Coalition, Mujahideen, and Kurdish Democratic Union Party have been engaging with the forces of the Syrian government through asymmetric means. The conflict has seen large-scale asymmetric warfare across the country, with the forces opposed to the government unable to engage symmetrically with the Syrian government and resorting instead to other asymmetric tactics such as suicide bombings and targeted assassinations.

Ukraine: The 2022 Russian invasion of Ukraine has resulted in a classical asymmetrical warfare scenario. Russia's superior military might, including its vast nuclear arsenal, larger economy and population, and seemingly superior armored forces have not helped Russia surmount fierce opposition from the Armed Forces of Ukraine, which has inflicted severe blows against the Russian Armed Forces by relying on technologically advanced weaponry supplied by the outside Ukraine supporting parties. The use of MAGURA V5 unmanned surface vehicles (USVs) to attack Russian Black Sea Fleet ships such as the Tsezar Kunikov has been cited as example of asymmetrical warfare by analysts.

Semi-symmetric warfare: A new understanding of warfare has emerged amidst the 2022 Russian invasion of Ukraine. Although this type of warfare does not oppose an insurgency to a counter-insurgency force, it does involve two actors with substantially asymmetrical means of waging war. Notably, as technology has improved war-fighting capabilities, it has also made them more complex, thus requiring greater expertise, training, flexibility and decentralization. The nominally weaker military can exploit those complexities and seek to eliminate the asymmetry. This has been observed in Ukraine, as defending forces used a rich arsenal of anti-tank and anti-air missiles to negate the invading forces' apparent mechanized and aerial superiority, thus denying their ability to conduct combined arms operations. The success of this strategy will be compounded by access to real-time intelligence and the adversary's inability to utilize its forces to the maximum of their potential due to factors such as the inability to plan, brief and execute complex, full-spectrum operations.

See also: 

References: 

Further reading: 

Bibliographies: Compiled by Joan T. Phillips Bibliographer at Air University Library: A Bibliography of Asymmetric Warfare, August 2005.
Asymmetric Warfare and the Revolution in Military Affairs (RMA) Debate sponsored by the Project on Defense Alternatives

Books: Arreguin-Toft, Ivan (2005). How the Weak Win Wars: A Theory of Asymmetric Conflict. New York & Cambridge: Cambridge University Press. ISBN 978-0-521-54869-4.
Beckett, I. F. W. (15 September 2009). Encyclopedia of Guerrilla Warfare (Hardcover). Santa Barbara, California: Abc-Clio Inc. ISBN 978-0-874-36929-8.
Barnett, Roger W. (2003). Asymmetrical Warfare: Today's Challenge to U.S. Military Power. Washington, D.C.: Brassey's. ISBN 978-1-574-88562-0.
Friedman, George (2004). America's Secret War: Inside the Hidden Worldwide Struggle between the United States and Its Enemies. London: Little, Brown. ISBN 978-0-316-72862-1.
Paul, T. V. (1994). Asymmetric Conflicts: War Initiation by Weaker Powers. New York: Cambridge University Press. ISBN 978-0-521-45117-8.
Schröfl, Josef (2007). Political Asymmetries in the Era of Globalization. Lang. ISBN 978-3-631-56820-0.
Kaplan, Robert D. (2003). Warrior Politics: Why Leadership Demands a Pagan Ethos. New York: Vintage. ISBN 978-0-375-72627-9.
Levy, Bert "Yank"; Wintringham, Tom (Foreword) (1964). Guerrilla Warfare (PDF). Paladin Press. Archived from the original (PDF) on 2014-04-12. Retrieved 2014-04-15.
Merom, Gil (2003). How Democracies Lose Small Wars. New York: Cambridge University Press. ISBN 978-0-521-80403-5.
Metz, Steven; Johnson II, Douglas V. (2001). Asymmetry and U.S. Military Strategy: Definition, Background, and Strategic Concepts (PDF). Carlisle Barracks: Strategic Studies Institute/U.S. Army War College. ISBN 978-1-58487-041-8.
Schröfl, Josef; Cox, Sean M.; Pankratz, Thomas (2009). Winning the Asymmetric War: Political, Social and Military Responses. Peter Lang. ISBN 978-3-631-57249-8.
Record, Jeffrey (2007). Beating Goliath: Why Insurgencies Win. Washington, D.C.: Potomac Books. ISBN 978-1-59797-090-7.
Giuseppe, Gagliano (2007). Introduzione alla conflittualita' non convenzionale. Edizioni New Press. ISBN 978-8-895-38302-6.
Resnick, Uri (July 12, 2013). Dynamics of Asymmetric Territorial Conflict: the evolution of patience. Basingstoke, U.K.: Palgrave-Macmillan. ISBN 978-1-137-30398-1.
Sobelman, Daniel (2004). New Rules of the Game: Israel and Hizbollah after the Withdrawal from Lebanon (PDF). Jaffee Center for Strategic Studies, Tel-Aviv University. ISBN 978-9-654-59057-0. Archived from the original (PDF) on 2012-11-02.
Sobelman, Daniel (2009). "Hizbollah – from Terror to Resistance: Towards a National Defence Strategy". In Jones, Clive; Catignani, Sergio (eds.). Israel and Hizbollah An Asymmetric Conflict in Historical and Comparative Perspective. Routledge. pp. 49–66. ISBN 9781135229207.
Sobelman, Daniel (Winter 2017). "Learning to Deter: Deterrence Failure and Success in the Israel-Hezbollah Conflict, 2006–2016". International Security. 41 (3): 151–196. doi:10.1162/ISEC_a_00259. JSTOR 26777793. S2CID 57571128.

Articles and papers: Bryant, G. J. (2004). "Asymmetric Warfare: The British Experience in Eighteenth-Century India". Journal of Military History. 68 (2): 431–469. doi:10.1353/jmh.2004.0019. S2CID 144222473 – via Project Muse(subscription required).
Arreguin-Toft, Ivan (Summer 2001). "How the Weak Win Wars: A Theory of Asymmetric Conflict". International Security. 26 (1): 93–128. doi:10.1162/016228801753212868. S2CID 51776546.
Dunne, J. Paul; García-Alonso, María D.C.; Levine, Paul; Smith, Ron P. (April 2006). "Managing Asymmetric Conflict". Oxford Economic Papers. 58 (2): 183–208. doi:10.1093/oep/gpi056.