Mr Saakashvili had to tread carefully in Ajaria because of a sprawling ex-Soviet base near Batumi, a legacy of the days when this was a cold-war frontier between the Red Army and Turkey, a NATO member.

ECONOMIST: The comic opera ends | The

Even in primitive northwestern Europe, where Rome stationed its army at frontier posts like Cologne, Mainz and Vienna, cash salaries and pension payments, plus the use of private businesses to supply food, arms and other necessities, ensured a city-centered, money-based market economy.

FORBES: Magazine Article

In 1939, the German army crossed the Czech frontier and Adolf Hitler proclaimed the protectorate of Bohemia and Moravia.

CNN: Saturday, March 15, 1997R

The army operates more or less freely on the frontier but is reluctant to touch Mr Mehsud.

ECONOMIST: Pakistan

For now, the army will not reinforce the 6, 000 troops in its frontier garrisons.

ECONOMIST: Colombia and its neighbours

The victims comprised of an assistant police sub-inspector and three members of the Frontier Corps, a paramilitary force which uses recruits from Pakistan's tribal areas and is overseen by Pakistani army officers.

CNN: Suicide attack kills 4 in Pakistan

And in the east, the Pakistani army is engaged in a sustained campaign against those same insurgents in one of the tribal territories along the frontier.

NPR: Series Overview: The Embattled Frontier