Merisodankäynti

Merisodankäynti, or maritime warfare, refers to the use of naval forces and maritime assets to achieve military objectives. It encompasses a broad range of operations, including sea control, blockades, amphibious assaults, convoy battles, anti‑submarine and anti‑aircraft warfare, and the use of specialized vessels such as aircraft carriers, submarines, surface combatants, and mine warfare craft. The core aim of maritime warfare is to deny the enemy freedom of movement at sea while securing one's own shipping lanes and strategic positions.

The concept originated with ancient naval battles, but modern merisodankäynti grew from the naval arms races of the 19th and early 20th centuries. In both World Wars, control of sea lanes proved decisive, leading to innovations such as convoy systems, depth charges, and the development of aircraft carriers. After World War II, the introduction of missiles, radar, and guided torpedoes further transformed naval tactics.

In contemporary conflicts, merisodankäynti remains a critical component of power projection for major naval powers. Integrated four‑domain warfare—combining sea, air, land, cyber, and space—requires coordinated operations among surface ships, submarines, naval aviation, and unmanned systems. The proliferation of asymmetric threats, such as piracy, terrorism, and regional naval expansion, has heightened the importance of flexible maritime forces capable of rapid response and sustained presence.

Finland, possessing a large Baltic Sea coastline, has traditionally engaged in merisodankäynti as a means of deterrence. The Finnish Navy focuses on coastal defense, maintaining fast attack craft, mine countermeasure vessels, and capable anti‑submarine operations. Finnish strategy places emphasis on littoral operations, mobility, and the capacity to restrict access to its territorial waters while safeguarding maritime trade and security interests. The doctrine stresses the importance of domain awareness, rapid information exchange, and the integration of naval, air, and cyber capabilities to defend Finland’s maritime sphere.