The soldiers were told to grow their hair long and were given civilian clothes. From then on, their superiors said, they would be addressed — and were to address one another — as “comrade tourist” as they sailed aboard a cruise liner to Syria.
With this simple trick, the Soviet Union managed to sneak thousands of soldiers into Syria in 1983 during the Lebanese civil war, in which Syria, Moscow’s close ally, was deeply involved.
I figure the Chinese will use this trick when they invade Taiwan.