NATO and Russian aircraft and ships have drawn ever closer in the skies and seas around Eastern Europe in recent years, engaging in a kind of cat-and-mouse game that has led to near misses.

A significant number of these encounters have taken place above the Baltics, where NATO members border a Russia they see as growing increasingly aggressive in its near abroad.

June alone saw several such incidents, including a Russian jet intercepting a US B-52 over the Baltic Sea early in the month, another Russian jet flying within a few feet of a US Air Force reconnaissance jet over the Baltic Sea in mid-June, and a NATO F-16 buzzing the Russian defense minister's jet later in the month.

Western officials and the research and advocacy group Global Zero — which analyzed 97 midair confrontations between Russian and Western aircraft over the Baltic between March 2014 and April 2017 — have said that Russian pilots are more often responsible for unsafe interceptions; some of which arise from negligence or are accidents, while some are deliberate shows of force.

"What we see in the Baltic Sea is increased military activity — we see it on land, at sea and in the air, and that just underlines the importance of transparency and predictability to prevent incidents and accidents,” NATO Secretary General Jens Stoltenberg told The Wall Street Journal. "And if they happen, it is important to make sure they don’t spiral out of control and create dangerous situations."

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Western officials and analysts believe Moscow is using such incidents as geopolitical tactics, responding to events in Europe and elsewhere, such as in Syria. Russia has denied this and said that recent reports about its abilities and activity in the region are "total Russophobia."

Both sides are working toward "risk reduction" policies for the Baltics. But the uptick in aerial encounters comes amid increased military activity by both sides on the ground in Eastern Europe.

Some 25,000 troops from the US and 23 other countries are taking part in the Saber Guardian military exercise in Bulgaria, Hungary, and Romania this month — the drills are designed as a deterrent and are "larger in both scale and scope" than previous exercises, US European Command said in June. US bombers also traveled to the UK in June in preparation for two separate multilateral exercises in the Baltics and elsewhere in Europe that month.

Those military exercises come ahead of war games planned for September by Russia and Belarus. Those exercises could involve up to 100,000 troops and include nuclear-weapons training.

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Neighboring countries have expressed concern that those war games could leave a permanent Russian presence in Belarus — the US plans to station paratroopers in Estonia, Latvia, and Lithuania during them and will adjust its fighter-jet rotation to put more experienced pilots in the area to better manage any encounters with Russian forces.

The US and NATO have increased troop deployments to Eastern Europe. UK and Canadian forces are headed to Poland, Latvia, and Estonia, and NATO personnel are already in Lithuania. The latter country has called for a permanent US military presence there as "a game changer" to counter Moscow.