The clash of wars...

When Terrorism and Counterterrorism Clash: The War on Terror and the Transformation of Terrorist Activity is a very insightful book and looks at everything, from guerrilla warfare to conventional methodology regarding military engagement.  It looks at various wars throughout history and takes a look at the war on terror that escalated after 9/11. 
A very compelling and educational read with a rich quantitative analysis of the largest ever terrorism database constructed for the period 1992-2004, the results of the study are fascinating and have important implications for current U.S. foreign policy in the Global War on Terrorism. Ivan Sacha Sheehan has examined in detail, with precise data, the impact of the use of pre-emptive force in the War on Terrorism in a rather unique light for the everyday reader. 
This is one of the first publications exploring the impact of the ongoing war on terrorism on the level, lethality and frequency of transnational terrorist activity around the globe. With extremely up-to-date data, When Terrorism and Counterterrorism Clash is a critical reference to all in the fields of international relations and political science.
Also looking further into the past (From Sun Tzu to Mao and their cunning/effective strategies...):  A look at modern wars such as the war in Iraq, the Vietnam war, wars in Afghanistan, Korean war,  Iran-Iraq war of the 80s,  Gulf war of the 90s... It takes us on a journey that explores every side and their various ways of doing things.  A worthy read and accompaniment for anyone interested in current and past conflicts, while getting to the heart of tactics, psychology and various examples of engagement.  (dissecting their consequences as well as any possible flaws or merits from past scenarios...)

Overall, When Terrorism and Counterterrorism Clash: The War on Terror and the Transformation of Terrorist Activity is also a very useful book, for any tactician or strategist (or anyone interested in the various psychologies/mindsets accompanying this dangerous game..), interested in the multifaceted murky depths of militaries or terrorists.  (Often those whom are deemed as terrorists view themselves as freedom fighters or rebelling against something they are radically opposed to...  This enemy being either militaries and various fighters, or falling into a rather complex grey area, where various groups change allegiances depending on their long-term/short-term goals/objectives.)  The big business built on blood and destruction regarding arms dealers (Or any contractors/parties involved in war/conflict profiteering...) who see war as an opportunity for profit, and view all sides as potential customers for ammunition and weaponry, also is a tragic reality still taking place with most ongoing hostilities.

Tactfully it delves into espionage, deception and how to keep up with the technologically advanced militaries, terrorists/fighters pitted against them have also had to advance and find various ways of obtaining intel.  (Those playing by the rules are sometimes outmatched by those who are not...  Other times the latest weapons and technology assure victory and superiority over any potential enemies...)

The geopolitical multi-dimensional manoeuvring seen by the big players in the World, such as America or Russia for example, have seen a constantly changing battleground when it comes to the middle east, (Syria, Iraq, Libya... In Europe the Ukraine...) and various proxies taking place that shift the balance of power in either direction regarding existing hegemonies.