The government, however, were at a loss to discover an ostensible pretext for the war; a pretext which they needed in order to satisfy the people, even although they had not been far too sagacious to undervalue, as was the manner of Philip, the importance of assigning a legitimate ground for hostilities.

The support, which Philip was alleged to have granted to the Carthaginians after the peace with Rome, manifestly could not be proved.

The Roman subjects, indeed, in the province of Illyria had for a considerable time complained of the Macedonian encroachments.
In 551 a Roman envoy at the head of the Illyrian levy had driven Philip's troops from the Illyrian territory; and the senate had accordingly declared to the king's envoys in 552, that if he sought war, he would find it sooner than was agreeable to him.

But these encroachments were simply the ordinary outrages which Philip practised towards his neighbours; a negotiation regarding them at the present moment would have led to his humbling himself and offering satisfaction, but not to war.

With all the belligerent powers in the east the Roman community was nominally in friendly relations, and might have granted them aid in repelling Philip's attack.