It's technically possible and practically feasible for scientists to choose the location where earthquakes will most probably occur. Earthquake and volcanic activity is increasing due to rising levels of atmospheric CO2 caused by runaway industrialization of the planet. Therefore scientists can now use coordinated HAARP electromagnetic waves to interfere with seismic processes and direct earthquakes towards an enemy's territory. Scientists can use HAARP to produce heat and water vapour in specific regions of the ionosphere and stratosphere. Expansion of the heated gases and vapour that forms in these regions causes these gases to push outwards into space and that creates an equal and opposite pressure down on the earth's surface. Repeated cycles of these HAARP pressure effects eventually induces fatigue cracking in the faults of the earth�s crust releasing swarms of small earthquakes that will regularly relieve the stress and strain accumulations along some sections of the tectonic plates so that stress and strain will build up in others sections. In other words they focus the accumulation of stress and strain at the location where they want a big quake to occur. The principles and techniques for doing this are all available and just require a top secret project to be strategically planned and executed under cover of a "sensitive science/military research program." Absolute secrecy would probably be the biggest challenge of all - not the technique of sending an earthquake to an enemy country, but the lengths to which the directors of the program would have to go to keep the program away from government scrutiny. That is difficult when several scientists in different countries would be required for successful execution and cover-up.
But consider the following - think how easily psychopathic mad scientists were employed in the secret military project for spraying and destroying millions of acres of rain forest, billions of animals, insects and birds and thousands of innocent people with horribly toxic chemicals in Vietnam. Or exposing sailors to nuclear radiation to see how the body reacts. Think how easily psychopathic mad scientists were employed in the secret geo-engineering projects 16 years ago for modifying waste water disposal and engine exhaust systems of modern jet aircraft to induce additional high level clouds in the stratosphere for cooling the earth. These vapours enhance HAARP atmospheric pressure effects. So this shows how easily psychopathic scientists can be recruited to do things like causing an earthquake in your enemy's territory.
There are dozens of articles blaming shale gas fracking for the recent increasing number of smaller earthquakes. I believe it is caused by HAARP pressure effects aimed at either keep large US cities safe from earthquakes or targeting enemy territories.