Seven Central and East European countries formally joined the North Atlantic Treaty Organization (NATO) on Monday, bringing the number of the organization's members to 26.

At a ceremony held in Washington and presided over by US Secretary of State Colin Powell, prime ministers of Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia deposited "instruments of accession" to NATO's founding treaty.

The seven countries have gone a long way to gain NATO membership. With the collapse of the Warsaw Pact more than a decade ago, east European countries lost their security guarantee and began leaning toward Europe for security and economic benefits.

But, to qualify for NATO membership, the seven countries had a price to pay. Large-scale military reforms were necessary.

Bulgaria, for instance, slashed its troops from 90,000 down to 50,000 and dismantled all its Soviet-made missiles. Romania signed a treaty with Ukraine to resolve its border disputes with the neighbor, giving up its claim over an oil-rich island in western Black Sea.

With the seven new NATO members, the European security scenario undergone significant changes. NATO expansion pushed the alliance's east border more than 1,000 kilometers eastward, putting NATO forces and Russia's northwest border into a face-to-face position and thereby triggering strong Russian reactions.

The direct contact between NATO and Russia has made the seven new NATO members' relations with Russia very delicate. The new member states are NATO's front runners in dealing with Russia but are also primary targets of Russian responses.

While the seven countries must perform its duty as NATO members to get NATO protection, they have to avoid excessively antagonizing Russia. The three Baltic countries, which welcomed NATO aircraft to protect their airspace and NATO bases on their territories, stressed that NATO would not deploy nuclear weapons in their countries.

Bulgarian leaders have repeatedly said joining NATO would not harm Bulgarian-Russian relations. Prior to Bulgaria's accession to NATO, its foreign minister visited Russia to boost ties.

NATO membership has earned the seven east and central European countries security protection from the military alliance, enabling them to cut down troops and defense spending and giving a boost to their national economy.

But their obligations have also grown. Bulgaria's chief of staff said Bulgaria will have to pay an annual membership fee of 8million US dollars and send 5,000 troops abroad on NATO peacekeeping missions.

Last December, Bulgarian forces in Iraq were hit by a suicide car bomb. The blast killed five people and injured another 26.

When voting on the country's entry into NATO, some Bulgarian parliamentarians said joining any military bloc meant taking risks.

More than 50 percent of the Bulgarian people are reportedly against joining NATO.

(Xinhua News Agency March 31, 2004)