>> what the -- is a disco stick? >> i think you know! >> reporter: back when they shared the "saturday night live" stage, their one upswomanship was all in frisky fun. but now, why do the two top divas seem to be waging a worldwide cold war? when it comes to setting it off you might say madonna was born this way. ♪ express yourself >> reporter: in tel aviv, her may 31 concert, madonna uncorked a mashup of the two songs trying to show perhaps just who paid the cost to be the boss. ♪ i'm on the right track baby i was born this way ♪ ♪ express yourself >> reporter: then in the pacific theater from new zealand, gaga, seemed to chide madonna. >> it sometimes makes people feel about themselves to put other people down or make fun of them