25 WHITE The U.S. was the first Ally to reinforce NATO air policing mission and deploy its troops, armament and equipment to the Baltic states as a demonstration of solidarity and assurance in response to Russia’s aggression in Ukraine in 2014. Poland is one of the main Lithuanian allies in the area of security and defence; defence cooperation with Poland contributes to the security of Lithuania and the region as a whole. Shared threats as well as the obvious need for common actions to respond to the emerging security challenges, unites Poland and Lithuania in the field of security and defence. Both countries have the same security goals in NATO and the EU, cooperate in contingency planning and development of military capabilities. Poland also contributes to NATO’s deterrence measures in the region. The U.S. allocates funding from the Foreign Military Fund, and since 2015 – from the European Reassurance Initiative for the strengthening of the LAF capabilities. Poland and Lithuania cooperate closely in the areas of acquisition, air defence, training and exercises. Lithuanian staff officers serve in the headquarters of the Multinational Corps Northeast located in Poland, which strengthens the regional expertise of the Alliance and provides the added capacity to develop command and control for collective defence operations. In the future, Lithuania is interested to further develop deeper ties with Poland in the defence area in order to promote The development of the Lithuanian Polish Ukrainian brigade (LITPOLUKRBRIG) not only strengthens trilateral cooperation but also contributes to the security and stability of the region. PA P E R